Stephen Holder

No. 1 overall draft pick Jadeveon Clowney of the Houston Texans made his intentions clear before ever playing in an NFL game, warning AFC South foe Andrew Luck to "have his head on a swivel" because the outside linebacker promised to take him to the ground.

Clowney, who is battling a serious knee injury, still hasn't gotten that chance. And Colts offensive tackle Gosder Cherilus says there's no guarantee Clowney ever will.

Perhaps you've heard about the microfracture knee surgery Clowney underwent this week. Well, Cherilus has actually experienced it.

And he's not optimistic about Clowney coming back.

"He's screwed," Cherilus, the Colts' starting right tackle said of Clowney. "His game is all about explosion. That's a problem. I'm out there dancing. I'm an offensive lineman. That's a different ballgame. He's screwed. I'm just being honest."

Cherilus sustained the injury that required the microfracture procedure in 2010. The surgery is intended to repair damaged knee cartilage in the area where bones meet. A tool is used to make small holes in the bone in an effort to promote the growth of new cartilage.

It's a common surgery for the general public, but it presents major obstacles for the elite athlete. History is littered with those who tried to come back from the surgery and failed (running back Reggie Bush and receiver Marques Colston are notable exceptions).

For a while, Cherilus thought he might join the long list.

"The doctor said, 'I'd be surprised if you ever play again'" Cherilus recalled. "I was like, 'My God.' But I gave it a try. We did rehab for nine straight months. Three to five hours in the morning and then I'd come back and do some more later. Think about that."

It was grueling even before beginning rehab, when Cherilus said he spent 10 weeks on crutches and was not permitted to put any weight on his leg. Doing so, he said, might have resulted in further damage and potentially require additional surgery.

"You see my leg right here?" Cherilus said. "Imagine putting this on crutches for 10 weeks. You lose everything. The whole leg was numb. I couldn't even walk. We had to teach the leg to do everything all over again: taking off, cutting, everything."

Even today, there is a constant reminder of what Cherilus has overcome. The soreness will always be present.

"There are days when it's cold and I definitely feel it," he said. "And I have to stay on top of my strength in the quad. That takes more pressure off the knee."

Cherilus thinks odds of a comeback are slim for Clowney, a player the Texans are counting on to help them close the AFC South gap between them and the Colts. But if Clowney is going to pull it off, it's going to take everything he's got – and then some.

"He has to be fully, fully committed," Cherilus said. "They told me I would be back in 12 months. I fought and came back in nine months. But it wasn't right. It set me back for another six weeks. You are going to deal with stuff for the rest of your career. Period. You're going to have to learn how to deal with it. And you have to be extremely disciplined. You have to do all the little things.

"Man, I'm telling you – it's hard."

Texans at Colts, 1 p.m. Sunday, CBS