The Falcons lost some defensive depth Tuesday, when they put defensive end Derrick Shelby on injured reserve with an Achilles injury. The team announced that they had promoted safety Sharrod Neasman to fill his spot on the active roster. The Falcons signed the former Dolphins defensive end to a four-year, $18 million deal early in free agency, and he had already shown good value as an interior rusher in sub packages. As much as they like to rotate their linemen, that’s a blow for a defense which has improved. Neasman went to camp with the Falcons as an undrafted rookie from Florida Atlantic, and was on the practice squad the first six weeks of the season.