Somewhere around 20 carries per game would be my guess.
Over the past two seasons, McCoy has carried the ball for an average of 19.5 carries per game.
http://www.nfl.com/player/leseanmccoy/79607/careerstats
Do you expect LeSean McCoy to get another 300+ attempts in 2015?
I'm not sure. He's a great back, but I don't want to run him in to the ground (or, 'until he pukes') either.
Who's the 2nd RB? Brown, Jackson, Dixon?
If McCoy gets injured, are any of the above running backs capable of carrying the ball 20 times a game?
I wouldn't be the least bit surprised if the Bills draft a running back in round 2 or 3.