According to Mike Klis, the Broncos have agreed to terms with Ryan Lilja on a one-year contract to join the team, presumably to compete for the starting center position. The Broncos have lost starter J.D. Walton for a significant part of the season, and recently lost presumed replacement Dan Koppen to a torn ACL. Manny Ramirez has been taking the starter's reps lately.
Lilja, who is a bit undersized at 6-2 and 290 pounds, played for the Colts from 2004 through 2009 primarily as a guard, and then joined the Chiefs for the 2010 through 2012 seasons. He had retired earlier in this offseason, so his signing is a reversal of that. Lilja rated as a 14.6 on PFF's scale last season, while playing center for the Chiefs. That's better than any Bronco has done at the position since Casey Wiegmann posted a 33.1 rating in 2008.
Update - 8:00 PM EDT - According to Klis, the maximum value of the contract is $2.2 million.