Dillinger's senior career began with the W-League's Indiana Blaze in 1997 where she played through 2000. In 1997, Dillinger started nine games in which she recorded three goals and two assists. In 1998, she started the final two games of the season after returning from Denmark. Dillinger played a leading role in helping the Blaze win the Central Conference and advance to the W-2 Final Four in 2000 where they finished third overall. She started at three different positions for the Blaze: center midfield, center back and forward. In 2000, she was third in points with four goals and four assists. In July 1999, she was named to the W-League Team of the Week alongside Charmaine Hooper and Danielle Dion of the Chicago Cobras.
In the summer of 1998, following her senior year at Indiana University, Dillinger headed to Europe to play professionally for Denmark's Fredericksburg Boldklub. She notched three goals and added three assists in five games to help Fredericksburg advance to the Elite Division.
In February 2000, the Women's United Soccer Association (WUSA) was founded by John S. Hendricks, chairman and chief executive of Discovery Communications, Inc. and became the world's first women's soccer league in which all the players were paid professionals. Dillinger was invited to the week-long combine held at Florida Atlantic University in Boca Raton, Florida December 5–9, 2000, during which 200 invitation-only players got the chance to participate in games and drills. It was during this combine that Dillinger recorded the first ever official WUSA penalty kick. At the end of the week, 120 of the players were selected in a 15-round draft to fill the roster spots.
Dillinger was not selected in the initial draft; however, she did receive invitations to try out for the Atlanta Beat and Carolina Courage in February 2001. She attended the Beat's invitation-only tryout which took place on the campus ofEmory University February 15–18 and consisted of 19 invitees from around the country. On February 19, the Atlanta Beat finalized their pre-season roster of 28 which included the addition of Dillinger along with Suzanne Eastman, Charry Korgel and Sarah Reading.
In the third and fourth matches of the pre-season at Agnes Scott College on Saturday, March 17, the Beat faced Vanderbilt University and the University of Florida. After playing 90 minutes in the first match of the double header, Dillinger made her mark less than five minutes after entering the second contest when she took a pass from Kylie Bivens and struck a 35-yard blast to the upper left corner past the Florida's goalkeeper for the game winner in the 61'. The team then traveled to Chula Vista, California for exhibition matches at the WUSA Preseason Tournament. Following the week-long tournament, teams would be required to cut their rosters to 20 players.
On March 25, 2001, in a match against the Bay Area CyberRays, the Brazilian connection of Sissi and Katia combined to take an early lead 16 minutes into the match. The Beat remained down by one for the next 54 minutes before Dillinger, who entered the game in the 60' for Charry Korgel, struck a shot from distance which deflected off CyberRays defender Thori Bryan and in to the back of the net. The score would remain tied 1-1.
On March 28, 2001, the Atlanta Beat defeated the San Diego Spirit 2-0 and moved to 8-0-1 in pre-season play. Dillinger scored the first goal from the penalty spot in the 10' to give the Beat a 1-0 lead. The penalty kick and ensuing red card were given when Spirit defender, Kim Pickup, made a dangerous tackle on Beat forward, Charmaine Hooper. Pickup was ejected from the match. Charmaine Hooper connected with Kerry Gragg for the second goal of the match. By the end of pre-season, Dillinger led the Beat in scoring with four goals.
On April 2 WUSA rosters were cut from 28 to 20 and the Atlanta Beat announced their final roster which included Dillinger as well as FIFA co-Player of the Century Sun Wen, US WNT players Briana Scurry, Cindy Parlow, Nikki Serlenga, former Canadian National Team Captain Charmaine Hooper, Japan's National Team's Homare Sawa, and Julie Augustyniak, Nancy Augustyniak, Kylie Bivens, Marci Miller, Sharolta Nonen, Dayna Smith, Lisa Krzykowski, Charry Korgel, Nicole Lamb, Kelly Cagle, Emily Burt, Kerry Gragg and Melanie Wilson.
Three weeks following the Beat's season opener at Georgia Tech's Bobby Dodd Stadium on Saturday, April 21 against the New York Power, Dillinger was released. Upon returning home, Dillinger underwent knee surgery. She was one of three Indiana Hoosiers to play during the inaugural WUSA season along with Tracy Grose, Carolina Courage and Kelly Wilson, Bay Area CyberRays.
In 2004, Dillinger concluded her playing career as player-coach for the W-League's St. Louis Archers. In addition to coaching soccer stars such as Lindsay Kennedy (St. Louis Steamers) and Beverly Markwort (Indiana University), she tallied four goals and three assists in six games. Dillinger officially retired in April 2005 after a patellar realignment.
Dillinger served as the assistant women's soccer coach at her alma mater Indiana University under Head Coach Joe Kelley for four seasons (1998–2001). During her tenure, she helped guide the Hoosiers to 35 wins, including an NCAATournament berth and the first NCAA Tournament win in school history in 1998.
Dillinger's responsibilities at IU included: individual technical and small group tactical training; contacting and evaluating prospective student-athletes; arranging and conducting official visits for prospects; scouting opponents; completing athletically related activity (ARA) logs; and arranging payment of match officials. She also served as the staff liaison with the athletic department compliance coordinator.
Dillinger wasted no time making her mark as the head coach of the Washington University in St. Louis women's soccer team. In six seasons on the Danforth Campus, Dillinger guided Washington University to a 86-25-8 overall record. She ranked 14th among active Division III coaches, winning 75.6 percent of her games. Exhibiting the balance between athletic excellence and academic excellence, in the last six years the Bears have captured four UAA Conference Titles on the field and in the classroom, four ESPN the Magazine Academic All-Americans, 10 Academic All-District Honors, and 68 Academic All-UAA Honors.
Dillinger's responsibilities at Washington University included: directing and coordinating the activities of the soccer staff in the planning, organizing and coaching of the soccer program; ensuring compliance with University, Conference and NCAA policies and regulations; scheduling all fall and spring intercollegiate contests; managing the women’s soccer budget and allocating funds for distribution toward uniforms, equipment, travel and officials; organizing, preparing, and conducting team practices, training, and competition; analyzing opponents (e.g. analyzing game statistics and tactical data of opponents and preparing appropriate game plan); recruiting student-athletes in accordance with NCAArules and regulations (e.g. campus visits, activities and meetings); consulting with the Director of Undergraduate Admissions in the recruitment process of prospective student-athletes; designing, overseeing and implementing the strength and conditioning program for all players; representing soccer program to various university divisions and externally to media, students, parents, and the general public; and counseling team members in academic, disciplinary and personal matters.
- 2002 - In her first year as a head coach, Dillinger guided the Bears to a 10-5-3 record (10-2-3 vs Division III opponents), including a 3-2-2 mark in the UAA. Washington U. remained in the hunt for a post-season bid until the final week of the season. The Bears allowed just 0.75 goals per game and recorded nine shutouts while outscoring their opponents 36-14. Three Washington University athletes were named to the All-UAA Second Team: Charlotte Felber (SO GK), Brenda Harpole (JR B) and Meg Lag (FR B). In addition to ten student-athletes earning Academic All-UAAHonors, three were named Academic All-District: Christine Vavra, Tana Mitby and Brenda Harpole.
- 2003 - Dillinger led WU to a 14-3-3 mark, and won the second UAA championship in school history. WU also advanced to the second round of the NCAA Tournament. Twelve Washington University student-athletes earned Academic All-UAA Honors, two of which were named ESPN the Magazine Academic All-Americans: Brenda Harpole and Christine Vavra. UAA Champions; UAA Coaching Staff of the Year; The Bears finished with an NSCAA Final National Ranking of 18th.
- 2004 - Dillinger and the Bears posted a 17-3-1 mark in 2004 and advanced to the Sectional Finals for the third time in school history before falling 0-3 to No. 6 University of Puget Sound. Washington University captured their third overall UAA Title and second under Coach Dillinger. In addition to setting a school record for Goals Against Average (0.51) and career wins (36), Charlotte Felber (SR GK) was named UAA Player of the Year and selected as an Academic All-American. Felber as well as Talia Bucci (SO B) and MeghanMarie Fowler-Finn (SO M) were named NSCAAAll-Region. Four student-athletes earned Academic All-UAA Honors, one of which, MeghanMarie Fowler-Finn was named ESPN the Magazine Academic All-District. WashU finished 12th in the final NSCAA National Rankings.
- 2005 - The Bears finished 11-7-1 (3-4-0 in UAA) outscoring opposition 32-12. Six of the seven drops were one goal games. Three players earned All-UAA recognition: Talia Bucci (JR M) and MeghanMarie Fowler-Finn (JR M) First Team and Caitlin Malone (FR F) Second Team. Bucci, Fowler-Finn and Nina Sass (SO GK) were all named All-Region Second Team. Eleven student-athletes earned Academic All-UAA Honors and MeghanMarie Fowler-Finn was named Academic All-District.
- 2006 - The Bears tied the school record for wins with a 17-3 overall record, including a 7-0 record in University Athletic Association (UAA) play, while outscoring their opponents 56-9. Dillinger and her staff (Carrie Marino, Lori Khazen and Chris Sellers) picked up UAA Coaching Staff of the Year honors after capturing the UAA title and advancing to the NCAA Sectional Semi-Finals before falling to Washington & Lee 1-2. Dillinger also helped mentorNSCAA First Team All-American, ESPN The Magazine Academic All-American, UAA Most Valuable Player and D3Kicks.com National Player of the Year, MeghanMarie Fowler-Finn (SR M). All-UAA Selections included Folwer-Finn, Talia Bucci (SR M), Caryn Rosoff (FR F) and Carrie Sear (JR GK) on the First Team and Libby Held (FR B) on the Second Team. Fowler-Finn, Bucci and Sear were also named NSCAA All-Region and Rosoff was awarded UAARookie of the Year. Twelve student-athletes earned Academic All-UAA Honors. The Bears finished the season ranked 11th according to the NSCAA Final Poll.
- 2007 - Washington University advanced to the NCAA Sectional Round for the third time under Coach Dillinger before falling to No. 3 TCNJ 0-1. Again tying a school record with 17 wins, the Bears finished with a final record of 17-4. For the fourth time in six years, Dillinger guided her team to a UAA Championship. Caryn Rosoff (SO F) garnered the honors of UAA Player of the Year and NSCAA Second Team All-American. She was also named First Team All-UAA alongside Libby Held (SO B) and Caitlin Malone (JR F). Carrie Sear (SR GK) and Carly Anderson (JR M) earned Second Team honors. Rosoff and Sear were named to the NSCAA All-Central Regional first team, while Held and Becca Heymann (SO M) earned third-team accolades. Nineteen (19) players earned All-UAA Academic Honors, one of which, Cassie Scaman (SO B) was named ESPN the Magazine Academic All-District. The Bears finished 9th in the NSCAA Final National Rankings.
Washington University's travel schedule under Coach Dillinger included trips to the states of Georgia, Illinois, Indiana, Iowa, Kentucky, Massachusetts, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, Washington and Wisconsin.
On January 24, 2008, senior associate athletics director Dr. Calli Sanders announced Wendy Dillinger as the new head women's soccer coach of the Iowa State Cyclones. She recorded her first win with the Cyclones at DePaul University on Friday, September 5, 2008 in a 3-1 victory. Dillinger also captured her 100th career win as a head coach on August 22, 2010 against Northern Iowa by a tally of 3-1.
- 2008 - Dillinger's first season as head coach of the Cyclones set in motion a plan to build a program founded on competitiveness and rooted in character, academics and the community. A final overall record of 5-12-2 (0-8-2 Big 12) included wins against two in-state rivals Drake and Northern Iowa. Seven players were named Academic All-Big 12, two of which, Ann Gleason and Lauren Fader, were named CoSIDA District VII Academic All- Americans. The women's soccer team did capture the coveted Cyclone Challenge Cup for community service.
- 2009 - The 2009 season witnessed steady improvement notching a 7-9-4 overall record (2-8-0 Big 12) with wins over No. 20 DePaul, Oklahoma State, and Texas and an overtime thriller against Northern Iowa. Final RPI 164.
- 2010 - 8-10-2 (3-7-0 Big 12) Final RPI 108.
- 2011 - The Cyclones took another step in the right direction during the 2011 campaign in dramatic fashion. The Cyclones finished the season with an even 9-9-1 (2-6 Big 12), set a season record for shutouts holding nine opponents scoreless, and ended the year with an RPI ranking of 78th in the nation. This was the first time in Big 12 history that all conference members were ranked in the top 100.
Iowa State's travel schedule under Coach Dillinger included trips to the states of Colorado, Illinois, Indiana, Kansas, Minnesota, Missouri, Montana, Nebraska, Ohio, Oklahoma, Texas, South Dakota and Wisconsin.