Mailbag: Who's behind Ryan Mathews?

Weekend mail call:

Kevin Ferrelli from Charleston, S.C. wants to know if I think the San Diego Chargers' backup running back situation is solid.

Bill Williamson: It’s not bad. The key is Ryan Mathews' health. I don’t think there is a solid starting answer other than Mathews on the roster, but there are plenty of players who are capable of carrying the ball a few times a game. I think Jackie Battle, Ronnie Brown, Curtis Brinkley and rookie Edwin Baker could all help this team and don’t forget new fullback Le'Ron McClain. He can carry the rock as well to give Mathews a breather.

James from Fresno wants to know if I think Peyton Manning's first season will be considered a failure if the Broncos don’t get past the first round of the playoffs as the Tim Tebow-led Broncos did in 2011.

BW: I think it would be difficult to say otherwise. But I think the big picture here is Manning’s entire time in Denver. If Manning’s health is strong after the season, it will be a positive. But there is no doubt the Broncos signed Manning to make a deep playoff run immediately.

Tommy from Kansas City wants to know if I think Jonathan Baldwin can catch 50 passes this season.

BW: I think that is reasonable. The Chiefs are giving to give Baldwin a chance to make a splash. After dealing with a broken thumb, Baldwin had 21 catches in 11 games. He had a good offseason and I think the Chiefs are going to give him all he can handle in 2012, so 50 catches is a steep, but reasonable, expectation.