Mailbag: Who is expendable?

Weekend mail call:

Baron from Sacramento wants to know if I think Ahmad Brooks can play inside linebacker while Navorro Bowman recovers from a torn ACL.

Bill Williamson: It’s interesting. Brooks did play some in the middle last season. But for the most part, he will stay on the outside while Bowman, who could be out for half the season, recovers. Brooks can make his biggest impact where he is, but again, the 49ers can get multiple in their schemes, so I wouldn’t be surprised to see some sequences where Brook is inside while Bowman is out.

Paul from North Dakota wants to know if I think the 49ers could trade LaMichael James to New Orleans as a replacement for Darren Sproles.

BW: I get why you ask. Sproles went to Philadelphia and James has potential to be a similar player. But I’m not sure what James’ market is going to be. At this point, the 49ers want to see if their 2012 second-round pick can help them or not. If James doesn’t make an impact on offense this year, the 49ers could be ready to move on.

Marc from Illinois wants to know who will be the lowest priority for contract extensions: Colin Kaepernick, Aldon Smith and Michael Crabtree.

BW: It’s an intriguing question. The ultimate answer is the 49ers want to keep all three. It can happen, although it may take using the franchise tag. The one player who potentially could not be extended is Smith. His off-field issues are well documented. The 49ers want to see him remain on the right track. So he could be the last one of the three to get an extension.