Williams watched in his jersey and shorts with a large bandage wrapped around the top of his right leg. The problem began Tuesday morning, and he was pulled from the field halfway through the workout.
"It's pretty tight, so we just wanted to calm it down," he said.
Williams, the No. 1 pick in last year's draft, said it was mostly a precaution and he wasn't worried about the problem lingering.
"I just don't want something to happen right now in training camp," he said. "This is a very important season coming up for the team, and I want to be a part of that. So I'm going to try to be as cautious as possible."
Coaches have been impressed with his recent work in practice as he makes the transition to playing right defensive end full time after moving around the line last season. He's much more relaxed since arriving in Houston amid the Reggie Bush/Vince Young controversy a year ago.
Kubiak was encouraged by Williams' work ethic throughout the offseason and said the player was disappointed about missing practice on Thursday.
"He actually wanted to go," Kubiak said. "He had his pads on. I made him go in and take them off this morning."
After thinking about it, Williams realized sitting out for a bit now would be better than risking injuring himself more. He has been working with trainers and getting treatment.
Expectations for Williams are high after a disappointing rookie season in which he had 47 tackles and 4 1/2 sacks. He started every game but was slowed by pain in his right foot.
That problem is behind him and he's hoping to also put this one in the past so he can return to a defense he thinks is much improved.
"Everybody is helping everybody else," he said. "It's not just a one-man show or anything like that. Everybody is out there doing what they got to do and supporting the players beside them."
The Texans got Williams some help on the defensive line by taking 20-year-old defensive tackle Amobi Okoye with the 10th pick in the draft. Williams, who is only 22 himself, likes having someone new around to be the youngster on the team.
And with a year of experience, Williams is ready to help Okoye out.
"He's a young guy, he's out there running around and coaches are on him," Williams said. "I'm sure his head is spinning. I think if he settles down he'll be fine. That's what I keep telling him."
Copyright 2007 by The Associated Press