Broncos starting center Dan Koppen will miss the 2013 season after tearing his left ACL in practice on Sunday, the team confirmed. Koppen was injured during a 9-on-7 drill and carted off the field, according to USA Today.
Koppen's season-ending injury leaves the Broncos short-handed and inexperienced at center. Koppen started 12 games at the position for the Broncos last season, but he was only playing because the center before him -- J.D. Walton -- broke his ankle in a Week 4 win over the Raiders.
Walton suffered a setback this summer and is still out, according to the Denver Post, which means Peyton Manning could be taking snaps from Denver's fourth team center if Koppen's out for any substantial amount of time. The current No. 2 center, C.J. Davis, was carted off the field with a lower-leg injury on Saturday.
For now, the Post reports that Manning will be taking practice snaps from Manny Ramirez until Koppen's injury situation is figured out. Ramirez is going into his sixth-year -- second with the Broncos -- but he's spent most of his previous five seasons playing guard.
The Broncos can also turn to second-year pro Philip Blake. Blake has been lining up at guard, but he does have plenty of experience at center. As a senior at Baylor in 2011, Blake started 13 games at the position, snapping the ball to Robert Griffin III.