The former Pilgrims youth product has been back on trial with Argyle in pre-season following his release by Southampton.
But having not featured in the Pilgrims' 0-0 draw with Bath, boss John Sheridan confirmed the 26-year-old's trial was over.
"I'm not going to be doing anything with Ryan," he told the club's official website.
"He's not really what I'm looking for. I've explained it to him the best way I can, and I'm working hard to try and fill that area."