Dan Koppen was placed on injured reserve Tuesday, ending his Denver Broncos comeback less than two months after re-signing with the team. Koppen tore his ACL during 9-on-7 drills as the Broncos began training camp.
The 11-year NFL veteran was signed when the Broncos found out that J.D. Walton wouldn't be recovering from ankle surgery as fast as anticipated as the team's prospective starting center. Denver will have to move on to Plan C now, handing the starting center duties over to Manny Ramirez.
Koppen's injury is unfortunately not the only one that Peyton Manning's offensive line is dealing with. Left tackle Ryan Clady is still recovering from right shoulder surgery he had in the offseason while right tackle Orlando Franklin and right guard Chris Kuper are recovering from surgeries of their own.
To replace Koppen on the roster, the Broncos signed free-agent center Steve Vallos. The 29-year-old out of Wake Forest has played for four teams during his five-year NFL career.