HOUSTON (AP) -- As the Houston Texans trickled into the locker room at halftime and learned that coach Gary Kubiak had collapsed leaving the field, their excitement over a big first half quickly disintegrated into dread.
They were soon informed that he was in stable condition, but the rattled team unraveled in the second half as Indianapolis rallied for a 27-24 victory Sunday night.
"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.
"We were all very worried," quarterback Case Keenum said. "When we went back out they told us he was ... stable. We were all upset about that but trying to stay focused at the same time."
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 was 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 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 value replacement surgery.
The 58-year-old Fox will have surgery in a few days and will miss several weeks while recuperating.
Fox had been told earlier about his heart condition and was hoping to put off the operation until February. As part of his trip to North Carolina over the Broncos' bye week, he met with his cardiologist in Raleigh and was told to seek medical attention immediately if he felt any discomfort.
On Saturday, Fox became dizzy playing golf near his offseason home in Charlotte and was taken to a hospital, where tests revealed he couldn't wait any longer to have the surgery.
Kubiak has long been known as a top offensive coach, mentoring quarterbacks in Denver under Mike Shanahan and now Matt Schaub - and Case Keenum - in Houston. Kubiak has had no known public health problems.
Kubiak was hired in 2006, along with general manager Rick Smith, after the Texans finished a franchise-worst 2-14. Smith spent 10 years with Kubiak while the coach was offensive coordinator of the Broncos. Smith was Denver's defensive assistant for four seasons before moving into the front office for his last six years with the Broncos.
The pair has helped transform the Texans, which began play in 2002, from league laughingstock to contender. The team went 6-10 in their first year and 8-8 in each of the next two seasons. Expectations were high in 2010 after Houston finished at 9-7 for its first winning record in 2009. But the Texans instead fell to 6-10, which led to many fans calling for Kubiak's firing.
His original contract was due to expire after the 2010 season, but owner Bob McNair has stepped up to keep Kubiak and defended him several times amid the bumps. Among recent departures were assistant head coach Alex Gibbs (for Seattle) and offensive coordinator Kyle Shanahan went to join his father, Mike, in Washington.
Kubiak hired former Denver offensive coordinator Rick Dennison to replace Shanahan and former Atlanta offensive coordinator Greg Knapp to become Houston's quarterbacks coach. Dennison worked on the Broncos' staff during Kubiak's 11 years as Denver's offensive coordinator, and Knapp coached Schaub for three seasons with the Falcons.
The highest-profile assistant brought to Houston was Phillips, the veteran son of Bum Phillips and a former head coach in Dallas.
Last year, the Texans announced contract extensions for both Smith and Kubiak, rewarding them for taking the team to the playoffs last year for the first time. Kubiak's three-year agreement has him under contract through 2014.
McNair said at the time he offered Kubiak a four-year deal, but the coach preferred to make it for three.
Kubiak made his mark as Denver's offensive coordinator under Shanahan, winning two Super Bowls. An eighth-round pick out of Texas A&M, he spent nine years as John Elway's backup. He finished his career 4-1 as a starter, all in emergency relief of Elway.