Two-time NFL sacks leader DeMarcus Ware announced his decision to retire Monday on Twitter.
"It's time," wrote Ware, who played 12 seasons with Dallas and Denver and won Super Bowl 50 with the Broncos.
Drafted 11th overall by the Cowboys in 2005, Ware made seven straight Pro Bowls from 2006-12. He led the league with 20 sacks and 15.5 in 2010, and was second in the NFL with 19.5 in 2011.
After joining the Broncos in 2014, Ware made the Pro Bowl two more times but he also struggled with back problems the last two seasons.
He retires at No. 8 on the NFL's all-time sacks list (138.5).