"That was tough because Scott Kooistra, we really liked and had been doing a good job for us," coach John Harbaugh said. "But he's more of a tackle-, guard-type guy. Can't play center. With Chris Chester's injury, we have a need for a backup center. We have a couple other guys that can snap as well. Tony [Moll] can do it, and Marshal [Yanda] can do it. But now, you get into a situation where if Matt Birk gets hurt, you've got to shuffle the whole offensive line.