Posted by ESPN.com's James Walker
Following the departure of center Jason Brown to the St. Louis Rams, up-and-coming quarterback Joe Flacco will be working with his second center in two years. The chemistry and rapport between a center and signal caller is vital to the success of any offense, and Baltimore didn't want to take a chance with the inexperienced Chris Chester, who only has nine career starts.
Birk, a six-time Pro Bowler, has spent his entire career with the Minnesota Vikings and has been one of the best at his position for the past decade. Birk is expected to help Flacco physically on the field and with the quarterback's mental development as well.