The Denver Broncos have turned to a familiar face to fill their sudden vacancy at center.
The Broncos agreed to terms with Koppen on Thursday, the team announced. NFL.com's Ian Rapoport reports it's a one-year contract, per a source close to the player.
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Koppen popped back on Denver's radar after J.D. Walton underwent additional surgery on his troublesome ankle last week. Koppen replaced Walton in October and started 12 games, just as Peyton Manning and the Broncos hit their stride on offense.
Koppen should be prepared for a full season of duty. The Broncos still are holding out hope that Walton will return by November, but that is believed to be a best-case scenario at this time. It's possible Walton won't play a down in 2013.
Koppen, 34, isn't a dominant player by any stretch (he graded out 22nd among centers last season, according to Pro Football Focus), but the Broncos are fortunate he was on the market as a fallback option.
Follow Dan Hanzus on Twitter @DanHanzus.