Rex Ryan mum on LeSean McCoy's MRI results, but optimistic about return

CLEVELAND -- Buffalo Bills coach Rex Ryan told reporters Thursday he is "cautiously optimistic" that running back LeSean McCoy can return in time for the Bills' regular-season opener Sept. 13 against the Indianapolis Colts.

McCoy suffered a hamstring injury in a joint practice Tuesday with the Cleveland Browns. Ryan did not reveal the results of an MRI on McCoy's hamstring, but had said after Tuesday's practice that McCoy's hamstring was intact and that no separation from the bone occurred.

The Bills were without their top five running backs for Thursday night's 11-10 preseason win over the Browns. Veterans Fred Jackson and Bryce Brown are both out with hamstring injuries, Boobie Dixon has a calf injury and rookie Karlos Williams underwent a medical procedure this week.

Jackson, Brown and Dixon could all return as soon as next week; Williams is out at least two weeks.

The Bills also were without their top three wide receivers for Thursday's game: Sammy Watkins (glute), Robert Woods (undisclosed) and Percy Harvin (hip).

Buffalo then lost wide receiver Chris Hogan late in the first quarter. He was carted to the locker room after suffering an ankle injury. Hogan, who was hunched over on the cart with a towel over his head, was ruled out for the remainder of the game.

Tyrod Taylor started at quarterback Thursday for the Bills and was replaced by EJ Manuel. Veteran Matt Cassel was in uniform but did not play, as was expected.