Upset with his contract in Green Bay and public criticism by Brett Favre of his threatened holdout, Walker came to Denver from the Packers in a draft-day trade in 2006.
His two-year stay in Denver was marked by a brilliant first season and the tragic shooting death of teammate Darrent Williams, who died in his arms.
Walker started last season with two 100-yard games before missing two months following a third operation on his right knee. He was supplanted by Brandon Marshall as the team's top receiver.
The Broncos also released linebacker Ian Gold, who spent seven seasons in Denver sandwiched around a season in Tampa Bay in 2004.