The Denver Broncos have placed center J.D. Walton on injured reserve with a broken and dislocated left ankle.
Walton was hurt just before halftime in the Broncos' 37-6 win over Oakland on Sunday when Raiders defensive end Jack Crawford inadvertently crashed into his legs as he was making the tackle on running back Lance Ball.
Walton was replaced by Dan Koppen, who was signed three weeks ago after his release by New England, where he spent nine seasons.
Replacing Walton on the 53-man roster is middle linebacker Joe Mays, who was suspended for Sunday's game for an illegal hit on Houston quarterback Matt Schaub.
Second-year tight end Virgil Green returned from a four-game suspension for violating the NFL's banned-substances policy. The Broncos have a roster exemption on Green.