Texans center Steve McKinney re-injured his left knee Thursday in the final 10 minutes of practice.
The injury occurred during a field goal drill in the south end of the Texans' indoor facility. McKinney was helped off the field by the training staff and then driven back to the locker room.
"We won't know until the trainers and the medical people go in and evaluate him," head coach Dom Capers said after practice. "I think he twisted his knee that he has the brace on. We'll go in and see how he responds and then make a prognosis.
"It just happened in a normal field goal-field goal blocking drill that we do on Thursday."
McKinney originally injured the knee in practice on Aug. 6, causing him to miss all four of the team's preseason games. But he returned to practice three days ago, expecting to reclaim his starting job. And he's still hoping to start Sunday at Miami.
""It hurts but it always hurts," McKinney said in the locker room after practice. "Right now my intentions are still to play. I'm going to try to suck it up and do whatever I have to do to go Sunday.
"I'd say it's up in the air right now but we'll see. It would be very upsetting. I haven't missed a season opener and obviously I don't want to start now."
"Basically, it was a live field goal (drill), which, honestly, I probably shouldn't have been in there," McKinney said. "My knee probably isn't 100 percent healed to be trying to do that, anyways. I was trying to do it and things happen, it's football.
"Somebody fell on the outside of my leg. We really don't know the severity of it yet. It might be just scar tissue. It might just be a Grade 1 slight sprain. We'll have to wait and see."