The New York Jets -- and their anxious fans -- can exhale.

An MRI exam Sunday revealed that rookie defensive lineman Leonard Williams has a muscle strain behind one of his knees, and the team avoided a potentially devastating injury to its first-round draft pick.

Williams got hurt in the first half of the Jets' 28-18 preseason victory over the Giants on Saturday night. The MRI showed no ligament damage to Williams' knee.

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There was no immediate timetable on when Williams might return, but it isn't expected to be a long-term injury. The Jets open the regular season on Sept. 13 at home against Cleveland -- giving him two weeks to rest and heal.

Coach Todd Bowles wasn't certain when Williams was injured, but the rookie was limping slightly and favoring his left leg as he walked behind the end zone and to the Jets' locker room after the Giants kicked off following a touchdown with 3:53 left in the first half. Williams never returned to the sideline after halftime, but X-rays on the knee were negative and he was receiving treatment in the trainer's room long after the game was over.

Williams, the No. 6 overall pick out of Southern California, is expected to be a major part of Bowles' defense. He has been starting for the Jets in place of Sheldon Richardson, who is suspended for the first four games of the regular season after violating the NFL's substance abuse policy.

Richardson is scheduled to be arraigned Monday in Missouri on charges of resisting arrest. The defensive lineman reached speeds as high as 143 mph in a road race on July 14, and later sped from police. Richardson could face additional discipline from the NFL for violating the league's personal conduct policy, so Williams could see an expanded role to start his rookie season if healthy.

Williams had 1 1/2 sacks, including a safety, in the Jets' second preseason game against Atlanta, and has impressed his teammates while having a solid training camp.

"He's so young, he doesn't realize the potential he actually has," Jets right guard Willie Colon said recently. "He has that Richard Seymour-type body, that prototype (body), and sky's the limit for the kid."