Cleveland Browns offensive coordinator John DeFilippo has insisted that Johnny Manziel is putting himself in a good position to revive his career having improved his work ethic.

The 22-year-old endured a miserable rookie season with the AFC North side, failing to earn the starting job out of training camp and struggling to impress when eventually handed his chance before ending the campaign on injured reserve.

However, Manziel checked into rehab for personal problems in the off-season and has come back to the Browns with a different attitude, which DeFilippo believes will pay dividends for his future in the league.

"All I know is this: From the moment he stepped in this building from the last two weeks, he's been nothing but a consummate professional," DeFilippo told reporters.

"He's spent every hour that he's been allowed to spend in this building. I can't predict the future, but all I can do is tell you right now Johnny Manziel is putting himself in a position to be a quarterback in the NFL."

Browns head coach Mike Pettine revealed that Manziel will start his side's training camp as backup behind veteran Josh McCown.