The Falcons are placing Derrick Shelby on IR with a torn Achilles, as Adam Schefter of ESPN.com tweets. The defensive end has been dealing with a calf injury that is apparently more serious than initially thought. 
Shelby, 27, left the Dolphins to sign with the Falcons in free agency this past offseason. Shelby, who took over for Cameron Wake after his injury, started eight games and performed well. PFF rated the former UDFA as its No. 23 overall edge-rusher despite Shelby starting just one game in his previous three seasons. Fellow Miami defector Olivier Vernon got all the headlines, but the Falcons were nonetheless excited about what Shelby could do this year.
In a related move, the Falcons are promoting rookie safety Sharrod Neasman from the practice squad to the 53-man roster, as Alex Marvez of NFL.com tweets.