Pettis, 27, is a former 2011 third-round pick of the Rams. The Chargers wound up signing him to a contract in January to add depth at receiver. However, he too was among the team’s final roster cuts.
Pettis worked out for the Patriots a few weeks ago, but didn’t receive an offer from them.
In 2014, Pettis appeared in five games and caught 12 passes for 118 yards receiving and one touchdown for the Rams.