Wochit News - Two players the San Francisco 49ers could not depend upon last year will be counted on to play big roles this season.Linebacker Aldon Smith missed the first nine games last season serving a suspension handed down by the NFL. Defensive lineman Glenn Dorsey sat out last season with a biceps tear.Patrick Willis, a linebacker, and defensive lineman Justin Smith retired after the season and defensive lineman Ray McDonald was released, leaving big holes to be filled.