Koppen signed with the Denver Broncos on Tuesday, two weeks after his release from the New England Patriots, where he played from 2003-11. NFL.com and NFL Network's Albert Breer reported Monday night that Koppen was close to signing a one-year deal with the Broncos.
Koppen, who turns 33 on Wednesday, adds experience and depth to the interior line and might push starting center J.D. Walton for playing time.
Manning was sacked twice in his Denver debut, once when it appeared the wrong line call shifted everyone to the right and led to left tackle Ryan Clady having no one to block. Running back Knowshon Moreno was left to block two men, and Pittsburgh linebacker Jason Worilds dropped Manning for an 8-yard loss.
The offensive linemen weren't in the locker room during the media access period Tuesday.
The Broncos also waived backup center C.J. Davis and re-signed backup quarterback Caleb Hanie, who was released in a procedural move Saturday to provide the Broncos with some financial flexibility. His $1 million base salary is no longer guaranteed.
As expected, the Broncos also placed defensive tackle Ty Warren on injured reserve after he re-tore his right triceps in the opener, his first game since 2009.
"It affects us a lot, actually," said second-year defensive tackle Mitch Unrein, who played a career-high 40 snaps after Warren got hurt. "He's a great leader. but as Coach (John) Fox always says, next guy up, so that kind of opens the door for guys like me."
Warren, 31, re-injured himself early in the Broncos' 31-19 win over the Steelers. He missed all last season after tearing the same muscle during training camp, and he missed the 2010 season, his last in New England, with a hip injury.The Associated Press contributed to this report.