Kansas City unfortunately lost Derrick Johnson for the entire season after he sustained a torn Achilles’ tendon during Sunday’s season opener.
Bishop, 30, is a former sixth-round pick of the Packers. He spent five years with Green Bay and helped them win a Super Bowl before he suffered a serious hamstring injury that cost him the 2012 season.
Bishop later caught on with the Vikings, but unfortunately suffered a torn ACL and was placed on season-ending injured reserve. The Cardinals signed him to a contract a few weeks ago and he managed to make through roster cuts, but was released just a few days ago.
Barnett, 33, signed on with the Redskins last year and appeared in 14 games before he suffered a MCL tear in December and was subsequently placed on injured reserve.
He recently found some interest from the Falcons, but there has been no reported progress in recent weeks.
Mitchell, 29, worked out for the Patriots and Titans a few months ago, but there has been little reported interest since the season drew closer.
He spent the 2013 season with the Vikings and appeared in 16 games while recording 41 tackles, a fumble recovery and a pass defense.