Detroit's bid for a Major League Soccer expansion team has abandoned its effort to build a stadium on the unfinished jail site downtown, and instead intends to use 64,500-seat Ford Field as the team's permanent home.

The abandoned 15-acre jail project site owned by Wayne County is still targeted for redevelopment, just without soccer.

An expansion soccer team playing inside the massive pro football stadium would buck MLS' preference for its new clubs to have soccer-specific stadiums, but adds the wealthy Ford family to the joint expansion effort led by billionaires Dan Gilbert and Tom Gores.

Crain's broke the news Thursday that Ford Field, home to the National Football League's Ford-owned Detroit Lions since it opened in 2002 at a cost of $500 million, would be at least a temporary home for the proposed MLS team in coming years. A statement from the expansion effort's backers made clear that Ford Field is now the preferred home for the team.

MLS is expanding by four cities, with two to be announced after the league's owners meeting in early December. Two more will be announced sometime after that, likely in 2018.

The expansion markets announced in December are intended to take the field in 2020. Arn Tellem, who works for Gores and is handling the expansion bid for the ownership group, previously told Crain's that Detroit's bid is for one of the 2020 teams. Using Ford Field means that's an easier goal than building the $1 billion stadium and mixed-use development pitched by Gilbert-Gores in 2016 for the jail site.

The Ford family involvement and Ford Field as the team's home was part of a supplement bid application given to MLS recently. The Fords could take an ownership stake in the team.

"Partnering with the Ford family bolsters our powerhouse group and provides a perfect stadium solution in the heart of Detroit's central business and sports and entertainment districts," Tellem said in a statement. "Over the last two years, we have invested significant time, effort and resources into our bid to bring MLS to Detroit. After careful study and analysis, we concluded that the downtown location of an MLS stadium is paramount to an MLS team's success. And no MLS stadium sits in a better downtown location than Ford Field. We also saw additional evidence that multi-use stadiums can be very successful in the right situation and we believe our new proposal is superior for the city and for MLS in every way."

A handful of MLS clubs play permanently at pro football stadiums, including the Seattle Sounders FC at 69,000-seat Century Link Field and the New England Revolution at 66,829-seat Gillette Stadium. Sections of seats are covered for soccer matches.

Ford Field has hosted soccer matches in the past, and is among the sites being considered to host 2026 World Cup matches.

A statement from MLS on Thursday indicates the league still prefers its teams to play in soccer stadiums.

"Although MLS has tremendous respect for the all of the owners involved in the Detroit bid, we have not had an opportunity to evaluate the amended application and it would be premature for MLS to offer a specific comment on it. MLS continues to prioritize soccer-specific stadiums as a criteria for the selection of MLS expansion markets," it wrote.

If Detroit does get a team, work would be done on the stadium to retrofit it for soccer match needs. MLS' 20 clubs last year averaged 21,692 fans per game. Attendance in 2016 ranged from 14,094 per game for FC Dallas to 42,636 for the Seattle Sounders. Teams that use pro football stadiums typically close off much of the seating to create a more intimate setting. MLS teams play 17 home matches in a spring-fall season.

Ford Field already underwent $100 million in renovations this year, mainly to its 129 suites, that was privately financed by the Ford family. The Lions play two preseason matches and eight regular-season games at the stadium each season, and it's also used for the occasional large concert. It also is home to several business offices.