FLORHAM PARK, N.J. -- When the New York Jets line up to play the Cleveland Browns on Sept. 13, their prized rookie -- Leonard Williams -- will be in uniform. That comes from a source familiar with the defensive end's injured knee -- Williams.

"Yeah, I'll definitely be ready by Week 1," he said Monday.

The former USC star, hurt in last Saturday night's win over the New York Giants, said he expects to miss five to seven days. It would've been something like five to seven months if he had suffered ligament damage, so he was relieved Sunday morning when the MRI showed no major damage, only a strained muscle behind his right knee.

"I was really concerned because I never felt any pain in my knees before," Williams said. "As soon as I felt that, I made sure I went to speak to the trainer right away. I was pretty concerned about it, especially when they took me to the X-ray room. That's when I got pretty nervous. But I'm glad everything is all right."

The Jets expect big things from Williams, especially with Sheldon Richardson due to miss the first four games because of a substance-abuse suspension. The starting defensive line figures to be Muhammad Wilkerson, Damon Harrison and Williams.

Williams spent Monday's practice in the rehab area, working with the other injured players. Missing practice is "a little bit of a setback," he said. He shouldn't be too concerned, though, because he's not falling behind. This is a 'tweener week, as they're between training camp and the regular season. In fact, several starters were given rest days on Monday.

Todd Bowles admitted he's relieved Williams didn't have a serious injury.

"I'm hopeful for Week 1," he said. "He said he's getting better by the day. When I see him running, I'll feel a lot better. Right now, he's walking pretty good."