This is Andrus' second term with the 49ers. He was signed before the last game of the 2009 season and made all four of his extra-point attempts against the St. Louis Rams. He also spent time last season with the Indianapolis Colts and Bucs.
The 49ers looked at two other kickers, Garrett Lindholm and Swayze Waters.
The kicking game figures to be crucial Sunday. Five of the Niners' nine games have been decided by three points or less. Four of the Bucs' games have been decided by that margin; they're 4-0 in those games.
Before signing Andrus, coach Mike Singletary said, "It's football. Guys get hurt. Unfortunately, it's Joe. The bottom line is that one of those guys is going to have to be the guy. And at the same time, there are other guys on our offense that have to step up. There are other areas on our special teams that guys are going to have to step up and make plays."
Andrus is 10 for 10 on extra points in his NFL career but missed his only field goal try.