Buffalo Bills running back LeSean McCoy tore his MCL in his right knee in Sunday's loss to the Washington Redskins and is now considered week-to-week for the final two weeks of season, a league source told ESPN's Adam Schefter.
More testing on McCoy's knee was scheduled for Monday.
McCoy took a hard hit to his knee on a tackle by Redskins defensive back Dashon Goldson in the third quarter following an 8-yard reception and remained on the ground.
He later jogged to the sideline under his own power, tested his injury under the supervision of the medical staff and then departed for the locker room, shaking his teammates' hands on the way.
McCoy rushed 10 times for 29 yards before his injury. He has rushed for 895 yards and three touchdowns in his first season with the Bills, who acquired him in an offseason trade from the Philadelphia Eagles.
ESPN's Mike Rodak contributed to this report.