PHOENIX – Plans to bring an MLS franchise to Detroit might never materialize, but the city could be ripe for another professional sports team.

So says the founder of the Alliance of American Football, at least.

In a Twitter exchange with Detroit-based rapper Eminem on Monday, Charlie Ebersol, a TV producer who founded the AAF, offered up the chance to bring a franchise to the city.

From February: New AAF league has Michigan ties

The exchange started when Eminem, whose real name is Marshall Mathers, tagged the AAF in a tweet asking the league to allow players to fight like in hockey.

"I WOULD WATCH EVERY GAME (EVEN THOUGH THERE IS NO DETROIT TEAM YET - HINT). DON'T BLOW IT," Mathers wrote.

Ebersol responded with a tweet of his own saying, "Detroit is not a bad idea for a future franchise. Let me know if you want in on it."

The AAF, which began play as a developmental football league earlier this year, currently consists of eight teams in mostly non-NFL markets like San Antonio, Orlando, Memphis, Tennessee, and Salt Lake City.

The league also has teams in Tempe, Arizona, near where the Arizona Cardinals play, and in Atlanta, home to the NFL's Atlanta Falcons.

It's unclear how serious Ebersol was about his proposal — an email seeking comment was not immediately returned — or why he thinks Detroit would be prime for an expansion franchise.

The city already boasts four professional sports teams, including the NFL's Lions, and a new team likely would have to contend with inclement weather for its home games (assuming it would play somewhere other than the Lions' home of Ford Field).

Seven weeks into its inaugural season, the AAF has gotten mixed reviews.

The league has enjoyed better than expected TV ratings, but it also has run into financial and legal challenges. Carolina Hurricanes owner Tom Dundon reportedly committed $250 million to the league amid reports it was having trouble making payroll and bleeding cash, and Ebersol was sued by a man who claims the league was his idea.

From a football standpoint, the AAF employs players who were largely marginal or worse players in the NFL, most of whom are looking for one final shot at the league.

The league also will face future challenges from startup leagues like the revamped XFL in 2020.

Contact Dave Birkett: dbirkett@freepress.com. Follow him on Twitter @davebirkett. Read more on the Detroit Lions and sign up for our Lions newsletter.