Sunday was not a very good day for the Buffalo Bills.

The Bills fell 31-20 to the Los Angeles Chargers in their home opener and saw their veteran cornerback literally retire at halftime.

Apparently their star running back endured a painful injury, too: LeSean McCoy suffered fractured ribs in Sunday’s game, NFL Media’s Ian Rapoport reported Monday morning.

As Rapoport notes, McCoy actually may try to play in Week 3 against the Minnesota Vikings. But he still was in considerable pain after the game, according to ESPN’s Mike Rodak.

The 30-year-old exited the game in the second half after Bills center Ryan Groy appeared to fall on him after a tackle. He briefly returned to the game but later left for good, finishing the day with 39 rushing yards on nine carries to go with 29 receiving yards on four catches.

The 0-2 Bills aren’t exactly deep at running back — Chris Ivory and Marcus Murphy are the other two backs who received carries Sunday — so they’ll be praying McCoy can battle through his ailment.

Thumbnail photo via Timothy T. Ludwig/USA TODAY Sports Images