The team waived/injured McKillop, a backup linebacker who underwent season-ending surgery on his left knee last Friday. If he's not claimed by another team, the Niners will place him on injured reserve for the remainder of the season. McKillop suffered a torn ACL and torn patellar tendon in his knee in a non-contact drill last week.
If a team claims McKillop, he'll be lost to the 49ers. He led the team with 31 special teams tackles last season.
To replace Long, the Niners signed wide receiver Bobby Guillory to a two-year contract. Guillory is a rookie free agent from the University of Central Missouri and is originally from Vallejo, Calif.