Atlanta Falcons offensive tackle Mike Johnson is officially out for the season after the club placed him on injured reserve Friday.

The move comes three days after Johnson fractured his left fibula and dislocated his ankle during Tuesday's practice session.

Johnson entered training camp as the Falcons' projected starter at right tackle in place of free-agent departure Tyson Clabo. Lamar Holmes, a third- round pick in last year's draft who played in just one game as a rookie, started at the position for Thursday's preseason opener against Cincinnati.

A third-round selection by the Falcons in the 2010 draft, Johnson saw action in 15 games while making one start last season.

Offensive tackle Jeff Nady, a rookie free agent out of Nevada, was signed by Atlanta in a corresponding move. The Falcons also placed rookie punter Sean Sellwood on waivers Friday.