ENGLEWOOD, Colo. --There are other injuries at other positions that would cripple the Broncos more than losing center Dan Koppen, who was lost for the season to a torn anterior cruciate ligament.
But given that Koppen was already the second option at the position after J.D. Walton, it's a haymaker at the crucial position that makes the checks and calls at the line of scrimmage.
Walton will be out until at least late October after undergoing a second surgery on his fractured right ankle. Given the setback he endured in recovering from the injury incurred last Sept. 30, the Broncos can't realistically stake their hopes on a successful and quick recovery, and likely have to regard Walton's possible return as a bonus that potentially provides a stretch-run boost.
Besides, the Broncos play nearly half the regular season before Walton could play, so they need a viable replacement.
Among the in-house candidates, Manny Ramirez is the most qualified, having started 11 games at right guard for Chris Kuper last year. With Walton shelved in the offseason, Ramirez handled the first-team center chores throughout OTAs and minicamp and was there again Thursday and Friday, and again Sunday after Koppen's injury. He knows the checks and the calls, but all of his regular-season starts in the NFL have come at the guard spots -- 24 at right guard and two at left guard between Denver and Detroit.
C.J. Davis can work at center and guard, and has the most experience working with Offensive Line Coach Dave Magazu; he came to Denver on Feb. 15, 2012 after spending 2009-10 under Magazu's watch in Carolina before being waived by the Panthers eight months after their 2011 coaching change. He stuck as a "swing backup" -- in the parlance of Head Coach John Fox -- last year and is a solid candidate to do so again, but first must return to the field after missing Sunday's practice with an ankle injury.
Other possibilities include 2012 fourth-round pick Philip Blake and 2012 practice-squad player Quentin Saulsberry, both of whom are short on experience. Blake handled some snaps with quarterback Brock Osweiler during Sunday's practice.
The free-agent market has been as thin as a supermodel since the Broncos signed Koppen last month.
Ex-Bengals center Jeff Faine is unsigned, but he hasn't been the same player since tearing his triceps muscle in 2010 when he was with the Buccaneers, and ranked last (36th of 36th) in Pro Football Focus' rankings of centers who took at least 25 percent of their team's snaps in 2012.
Former Titans center Eugene Amano went unsigned after missing all of 2012 with a torn triceps muscle. He had his ups and downs during his time as a starter, although he improved in 2011, his second season as a full-time starter there after working most of his first six seasons at guard.
Another name of note is former Chiefs center Ryan Lilja, who announced his intention to retire last December. According to The Kansas City Star, the Chiefs and Lilja discussed bringing him back in the spring, but tabled the notion while he recovered from toe and knee injuries. Lilja was a Colts guard from 2004-09.
Another possibility lies in what the Broncos did last year when they first signed Koppen: waiting until after the final cut to a 53-man roster. The Broncos didn't add him until Sept. 11, and he was ready to contribute extensively 19 days later. But that doesn't solve the problem of having a starter for the beginning of the season. The Broncos will examine the waiver wire after cuts, but that would likely only be for depth.