The defensive end is Josh Boyd, a 2013 fifth-round pick out of Mississippi State by the Green Bay Packers, who has not been on a team so far in 2016.
The linebacker is Ron Thompson, an undrafted rookie out of Syracuse, that spent time in the offseason with the Indianapolis Colts.
The safety is Dezmen Southward, a 2014 third-round pick out of Wisconsin by the Atlanta Falcons. Southward spent his rookie season with the Falcons, and he split 2015 with the Falcons and the Colts. He is yet to play in 2016.
The timing of the moves raises concern that both Joseph and Calhoun could miss extended time, and possibly the rest of the season. But hopefully this is nothing more than a precaution.