Financial terms were not disclosed.
Lilja retired after the 2012 season, ending an eight-year career. He underwent toe and knee surgeries this offseason.
Lilja was the Indianapolis Colts' starting left guard from 2004-09, so he has some familiarity blocking for Broncos starting quarterback Peyton Manning. In his last three seasons with the Kansas City Chiefs, Lilja played right guard, left guard and center. He has started 104 of 111 career games in his NFL career, including 12 games at center for the Chiefs last year.