IRVING, Texas (AP) -- Dallas offensive lineman R.J. Dill, a third-year player who hasn't appeared in an NFL game, has been suspended four games for violating the league's policy against performance-enhancing drugs.

Dill said Friday that he failed a drug test in May, about six months after he said he underwent testosterone replacement therapy when he was not under contract with a team. He said the NFL denied his request for a therapeutic use exception.

The Cowboys signed Dill in January. He is eligible for the rest of preseason practice and the two remaining exhibition games.

Dill signed as an undrafted free agent with Jacksonville in 2013 and spent time on New England's practice squad that year. He was cut late in camp by St. Louis last year.