Wide receiver Andre Johnson left the Texans' Week 4 game against Pittsburgh in the first half with what was termed a right hamstring injury. He did not return.
Johnson was injured with 6:10 left in the second quarter after a 13-yard catch. He fell to the ground untouched and started clutching the back of his right leg near the knee and writhing in pain.
"All I can tell you right now is we think it's hamstring related," Texans coach Gary Kubiak said. "It's in the lower leg. We will go and get an MRI and stuff this evening... Obviously, we have to find out what's going on."
A five-time Pro Bowler, Johnson was down on the field for a couple of minutes before getting up and walking to the sideline under his own power. He went to the locker room for further examination and returned to the sideline in street clothes in the fourth quarter.
"There is going down, and then there is going down," Kubiak said. "The way he went down was deflating because it was like he just got shot, so that scares the heck out of you. We were playing well as a football team and we had two-and-a-half quarters of football left to play. It's very difficult.
"He's the leader of this team and has been a leader of this franchise for a long time. Now if we have to go without him for a period, we're going to have to really ask some guys to step up to the plate."
Johnson had four catches for 36 yards before leaving the game. No other Texans wide receiver caught a pass. Tight end Owen Daniels led the team with five catches for 69 yards and a touchdown.
"I guess the next guy up needs to step up and step into his place," Daniels said. "You can't replace 'Dre, obviously. He's an unbelievable player and he creates so many problems for defenses, so everyone needs to do a little bit more now. I think that's what we all said to each other when he went down, 'We all need to step up and put a little extra effort into it,' and I think that's why we came out on top today.
"For however long he's out for, if it all, it's gonna take a litlte extra effort from everybody."