Texans coach Gary Kubiak was in stable condition after he collapsed leaving the field at halftime of Houston's 27-24 loss to Indianapolis on Sunday night.
Now the reeling Texans, losers of six straight, are left to worry about their coach and wonder when he'll return to the team.
"There was a lot of unknown," said defensive coordinator Wade Phillips, who coached the team after halftime. "Everything was unknown as to what was going on and what happened to Kube."
Kubiak hunched over and dropped to his knees at the 24-yard line and was immediately surrounded by medical personnel. He was lifted off the field on a stretcher and taken by cart to the ambulance.
"It's on your mind when you're out there playing," receiver Andre Johnson said. "But you try to focus on the game and just go out and do your job."
The Texans didn't say what was wrong with Kubiak, but did say he didn't have a heart attack. The team said the 52-year-old coach, a former NFL quarterback who calls the team's plays, was conscious and with his family as he was taken to the hospital.
"He had an episode; he was light-headed and dizzy," Houston general manager Rick Smith said in an interview on NBC. "He was evaluated by a number of specialists ... he is awake and coherent.
"We have to assess ... obviously, there's a lot of info. Hopefully, Gary will be back with us tomorrow."
Up 21-3 when Kubiak collapsed, the Texans struggled after halftime for their sixth straight loss after opening the season 2-0 with Super Bowl hopes.
Veteran safety Ed Reed didn't want to blame the loss on what happened to Kubiak.
"I thought we dealt with it well," Reed said. "We've just got to finish."
Kubiak's collapse came a day after Denver Broncos coach John Fox was hospitalized in North Carolina as he awaits aortic valve replacement surgery. The 58-year-old Fox will have surgery in a few days and will miss several weeks while recuperating.