Johnson dislocated his left ankle and broke his left leg in Tuesday's practice. He will have surgery next week.
Following Johnson's injury, Lamar Holmes moved up as the starting right tackle in the Falcons' 34-10 preseason loss to the Cincinnati Bengals on Thursday night.
The Falcons made two other moves on Friday, signing offensive tackle Jeff Nady and waiving punter Sean Sellwood.
Nady originally signed with Jacksonville as an undrafted free agent from Nevada, where he started 36 games. Sellwood signed with the Falcons as an undrafted free agent from Utah.
http://accesswdun.com/article/2013/8/264363