Coach Jeff Fisher said Friday the Rams picked up Young before they had much time to do any background checks. He said Young was "not the best option" for the Rams.
Young was banished three times by the Lions last year because of his behavior, including once for punching teammate Louis Delmas. He recently lashed out at the team on Twitter.
The Rams could be thin at wide receiver with Danny Amendola and Brandon Gibson unrestricted free agents. Fisher said he wasn't concerned about depth, adding that he would like to re-sign Amendola and running back Steven Jackson.