Luke Mishu (DCU)

Luke Mishu, an outside back who started five of D.C. United’s last 10 regular season matches this year, has retired after just two MLS campaigns in order to pursue career opportunities outside of soccer.

“I had to be realistic. I love soccer, but MLS isn’t the NFL or NBA,” he said Tuesday. “I felt like I could play until I was 30-whatever, but I didn’t want to leave the league needing to get an entry-level job.”

Mishu, 25, is aiming to enter the business world, preferably in Chicago.

As an undrafted reserve in MLS, he was earning the senior minimum salary of $62,500.

Average pay in the 20-year-old league is about $315,000, but with a handful of marquee contracts skewing the numbers, the median figure is $117,000. About half of United’s roster earned less than $100,000 this year.

For a borderline prospect like Mishu, long-term economic prosperity awaited outside of soccer. He told United officials of his decision during end-of-the-year meetings last month.

“If playing was only about my heart, I would play until I couldn’t walk anymore,” the Tennessee native said. “But I have to think about the future.”

Mishu graduated from Notre Dame two years ago with a degree in psychology while pursuing a supplementary major in the sciences and a minor in business-economics. He had a 3.5 grade-point average.

Mishu won an NCAA title with the Fighting Irish in 2013 and, with one year of playing eligibility left, enrolled in graduate school at Notre Dame. He served as a tri-captain in 2014, started every match for the third consecutive year and earned third-team academic all-America honors.

As an undergraduate with no thoughts of becoming a pro soccer player, Mishu had taken the prerequisite courses to enroll in medical school. He put those plans on hold after accelerating on the field and breaking into MLS. In 2015, he was a late invitee to United training camp and earned one of the last roster spots.

In his rookie season, he appeared in, and started, two league matches. This year, he wasn’t used in the regular season until late in the summer, when right back Sean Franklin and left back Taylor Kemp missed time with injuries. Mishu started three times on the left and twice on the right, and also subbed into two games.

United had projected him filling a similar role next season, providing backline depth and making spot starts, particularly in non-league competition, such as the U.S. Open Cup.

He’s no longer intending to apply to medical school, but as he tests the business waters, he said he might realize he needs to pursue another degree.

His soccer days are not over, however. He is joining his brother Mark (a Notre Dame senior defender) and several friends for a 3-v-3 tournament in Orlando next month.

In other United news …

The club declined the contract options on goalkeeper Andrew Dykstra, defender Chris Korb and midfielder Miguel Aguilar.

Korb, a 96-game starter at the left and right back positions between 2011 and ’15, has been sidelined for more than a year with knee problems and plans to pursue a new contract in D.C. training camp.

Aguilar, a two-year pro who spent the bulk of his time this year on loan to the third-division Richmond Kickers, might receive an invitation to United training camp. He has also attracted trade interest in the league; the Houston Dynamo reached out in the past year.

With a U.S. wife, the Mexican winger is awaiting permanent residency. Until then, he will continue to count against the international roster limit — a status that compounds the challenges for a young player trying to break into the league. Aguilar came to the United States as a minor from Ciudad Juarez and was allowed to stay under DACA, Deferred Action for Childhood Arrivals, a policy introduced by President Obama in 2012.

Aguilar appeared in 17 league matches in 2015 but only six this year.

Dykstra, 30, has been with United for five years, primarily as Bill Hamid’s back-up. With Hamid out with a knee injury to begin the 2016 campaign, Dykstra started in the CONCACAF Champions League quarterfinals and the league opener at Los Angeles. Back surgery then sidelined him for several months, allowing Travis Worra (13 league starts, four shutouts) to rise on the depth chart.

Dykstra is eligible for the MLS re-entry draft, Dec. 16 and 22.

United officials say they’ve been approached about trading forward Kennedy Igboananike, who joined the club in late July and made seven league appearances (one goal). His previous club, the Chicago Fire, was responsible for his $800,000 base salary this year. United has no plans to pay him anywhere near that figure next year.

Meantime, United is waiting to see whether Franklin will accept a new contract offer or enter the free agent market. The amount of the offer was not disclosed; he had a base salary of $225,000 this year ($257,000 in total compensation).

Any player age 28 or older with eight years of MLS experience can opt for free agency. Franklin, who turns 32 in March, has started 80 league matches in three seasons with United after six years in Los Angeles.

United is also in the process of finalizing its 11-man protected list ahead of next Tuesday’s expansion draft. Ten of the 20 current teams will lose one player to Atlanta or Minnesota, the other 10 won’t lose anyone.

Four D.C. players are exempt from selection and do not have to be protected: homegrowns Jalen Robinson, Chris Durkin and Collin Martin, and Generation Adidas draft pick Julian Buescher. Hamid was a homegrown signing but graduated to the senior roster and must be protected.