Denver Broncos center J.D. Walton missed all but four games last season after fracturing his ankle in late September. There's now a chance he will miss the 2013 season after undergoing additional surgery on the same ankle last week, Jeff Legwold of The Denver Post reported Wednesday.
The Broncos still are holding out hope that Walton will return by November in a best-case scenario, but they have to be prepared for a season-long absence.
The loss of Walton is not a major blow to the Broncos' Super Bowl chances, as the offense hit its stride with veteran Dan Koppen taking over the pivot from October through the end of the season.
Koppen, who turns 34 in September, has drawn little interest on the free-agent market and remains unsigned. The Broncos figure to kick his tires, but they have other options as well. Veteran right guard Chris Kuper was billed as a potential cap casualty after the addition of Louis Vasquez in free agency. He might be a necessity now.
If the coaches opt not to try Kuper or left guard Zane Beadles at center, 2012 fourth-round draft pick Philip Blake and long-time backup Manny Ramirez would move into the spotlight.