Report: Broncos C Dan Koppen exits with injury

Broncos starting center Dan Koppen was “carted off with [a] leg injury” on Sunday, Mike Klis of the Denver Post reported. The nature and seriousness of the injury is not known. Koppen, 33, started 12 games for the Broncos in 2012 in place of J.D. Walton, who suffered a broken ankle vs. Oakland on Sept. 30.…