Drakeford (6-1, 250) spent time on the practice squads of the Chiefs, Giants, and Colts during the 2013 season. He had eight sacks and 171 tackles for Maryland from 2009-12.
Castillo was signed as an undrafted free agent on May 12 and had two field goals in the Falcons' 16-10 preseason victory over the Miami Dolphins on Friday night.
AP NFL website: www.pro32.ap.org and www.twitter.com/AP-NFL
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