FORT WORTH, Texas — Texas Christian University and Southern Methodist University postponed their September 11 game as TCU announced Friday a cluster of Horned Frogs players and team support staff tested positive for the coronavirus.

TCU did not identify who was infected with COVID-19 or how many players or staff are involved. Athletic director Jeremiah Donati said none currently faces serious health issues.

No makeup date for the game at TCU was immediately set.

The postponement came at nearly the same time the Big 12 formally announced 53-player minimum roster to play a game, game, including all scholarship and walk-on players. The league also set minimums for the number of available offensive linemen (seven), defensive linemen (four) and quarterbacks (one).

TCU school officials this week reported more than 400 active COVID-19 cases for the campus two weeks into the fall semester. Among those, nearly 250 were students were living on campus.

Donati aid the TCU football program was aggressive in its testing and contact tracing protocols, and would “continue our enforcement of strict standards to protect the program and our community. Everyone’s health and safety remains our top priority.”

Donati said the schools will try to reschedule at a later date, although they may be few options. TCU is scheduled to play its Big 12 opener Sept. 26 against Iowa State. SMU plays Saturday at Texas State.

SMU athletic director Rick Hart tweeted the Mustangs were disappointed the game won’t be played as originally scheduled.

“Our student-athletes, coaches and fans were looking forward to the 100th edition of the Iron Skillet Rivalry. We are excited to start the season tomorrow at Texas State,” Hart said.

The TCU-SMU game is just the latest one affected by the pandemic. The North Carolina State at Virginia Tech game in the ACC was moved from Sept. 12 to Sept. 26 and Marshall and East Carolina postponed their Sept. 12 but no makeup game has been set.

The Big 12, the ACC and the Southeastern Conference are the only three Power Five conferences that opted to try to play in the fall amid the coronavirus pandemic. The Big Ten and Pac-12, as well as virtually every other lower-level conference, have put off fall sports and are instead hoping to play in the spring.