Johnny Manziel is still learning and adjusting to being a professional football player.

Dallas Cowboys legendary running back and Hall of Famer Emmitt Smith says the Cleveland Browns rookie quarterback will learn one important lesson about living a celebrity lifestyle in the NFL.

"That lifestyle is going to be a short lifestyle -- a short career lifestyle -- if he continues that," said Smith on KRLD-FM on Tuesday. "As we used to say, you can't keep burning the candle at both ends of the stick. The candle gets small fairly quick. So, Johnny is going to have to figure it out."

Manziel wasn't shy on social media about going to parties and high-profile events during his time at Texas A&M. And he hasn't shown he's ready to give up the college life despite leaving after his redshirt sophomore season.

Since the NFL Draft, Manziel has been seen back to his old ways, poolside in Las Vegas, Austin, and enjoying life across the country.

"Hopefully he's not doing anything to hurt himself outside of drinking, which is going to harm his body and harm his performance anyway," Smith said. "But at the end of the day, he's going to have to learn to manage those things.