Cleveland Browns quarterback Johnny Manziel has seemingly said and done all the right things this offseason after stumbling, bumbling and fumbling his way through an abysmal rookie season which saw him complete just 18 balls for 175 yards, tossing two interceptions and losing one fumble.

Things somehow got worse after the season, as reports detailing Manziel's allegedly childish and immature behavior gave way to an unexpected rehab stint. Upon his return from that self-imposed banishment, Manziel did his best to pick up the pieces of his NFL career.

He moved from downtown Cleveland to a more suburban neighborhood on a golf course and he recently retired his trademark "money sign" celebratory gesture. All the superficial work Manziel has put in this offseason has supposedly yielded tangible results as more than one veteran Browns teammate has suggested that the former Texas A&M star is making progress and finally showing signs of acting as a professional should.

To hear former NFL quarterback Elvis Grbac tell it, that jump from college standout to highly-compensated professional is the hardest Manziel is likely to face.

"It's obviously a learning experience," Grbac said during a break at the A4 passing camp in Ann Arbor last week, via Michael Rothstein of ESPN. "I think he's going in the right direction. He's on the right path. I think it'll be somewhat of a rude awakening the first couple games of the season and he will have to adjust.

"Going from the college level to the professional level is a huge jump, and you need to act like a professional. You need to prepare like a professional, and he will learn that as the years go on."

There's simply no doubting that Manziel fell well short of acting like a professional in Year One.

Whether he can make good on the promise that made him a first-round pick just last year in Year Two likely hinges very much on his ability to approach his practice and preparation this year like a mature pro, especially because of the target likely to be on his back if he makes his way onto the field in place of expected starter Josh McCown.

"What goes through my head is that everyone is kind of licking their chops, like the Steelers, I know they can't wait to play them," Grbac said. "Especially in that division, you have an extremely tough division. I think he's humbled himself a little bit. He's not doing the money sign anymore and all of that.

"So we'll see. But is he acting a little bit more professional? Maybe he is."