Cleveland Browns running back Trent Richardson has been ruled out of his side's pre-season opener against the St Louis Rams as he continues his recovery from injury.

Richardson had previously expressed his desire to play in Thursday's game, claiming that he was fit enough for a match situation as he looks to get ready for the new season.

However, coach Rob Chudzinski believes that the best course of action is to play it safe in order to minimise any chance of aggravating the injury further.

"We're going to be smart," said Chudzinski, according to The AP.

"It's the pre-season, we have a plan of working him and making sure that he gets reps as needed out here in practice and we build him to be ready for the beginning of the season."

Richardson was the third overall pick in last year's Draft but suffered an injury-hit rookie season.