Barnes played in 11 of 12 games this season. He had three sacks among six total tackles, including two sacks against Baltimore on Nov. 25.
A 10-year veteran, the 6-foot-4, 318-pound Wells spent time with the Chargers earlier this season, but did not appear in any games. Originally a sixth-round selection by Arizona out of Clarion, Wells spent the first seven years of his career with the Cardinals. In 2010 he was traded to the Philadelphia Eagles, and most recently spent the 2011 campaign with the Carolina Panthers. Prior to this season, he had appeared in 117 games and made 91 career starts. Wells went to training camp with the Green Bay Packers in 2012 before he signed with the Chargers.
Wells will wear No. 74.