Walton broke his ankle last September after playing in 36 straight games to start his career. He had a setback on the ankle in the offseason and underwent a second surgery in June and missed all of training camp and preseason.
The Broncos still hope he can come back in the second half of the season, but for now their depth at center is thin. Dan Koppen tore his ACL in camp and will be out for the year, leaving the Week 1 starting job down to Manuel Ramirez. The team signed Ryan Lilja and traded for the Seahawks' John Moffitt as insurance. Both players have experience at both guard and center, but they have their own injury issues. Lilja underwent microfracture surgery in the offseason, and Moffitt's original trade to the Browns was voided after failing a physical.