McCargo, 28, spent the first five years of his career with the Buffalo Bills, who drafted him out of North Carolina State in 2006. Over 40 games, he totaled 47 tackles and 2 1/2 sacks.
The Bucs revealed on Monday that McCoy was going to miss the remainder of the season with a torn biceps and was subsequently placed on injured reserve.
The second-year Oklahoma product sustained the injury to his right arm in the opening quarter of the Bucs' 27-16 loss to New Orleans on Sunday.
In related roster moves, Tampa signed running back Nic Grigsby and defensive tackle Swanson Miller to the practice squad.