Coach Dick Jauron said the player sustained a cervical spinal injury, and remained in hospital under observation. Jauron wouldn't discuss the severity of the injury or whether the player was able to move his body en route to hospital.

The player's agent Brian Overstreet was not immediately available for comment.

Everett fell to the ground and never moved after a helmet-to-helmet hit when he tackled Denver's Domenik Hixon during a kickoff to open the second half. Everett was placed on a backboard with his head and body immobilized, and carefully loaded into an ambulance at the Broncos 30.

The game was delayed for about 15 minutes, and the Bills gathered at the sideline while doctors attended to the player.

Everett's injury cast a pall over the Bills following a season-opening 15-14 loss, with several players expressing concern about their teammate.

"It was real hard," cornerback Terrence McGee said. "I watched the whole thing and he never moved. ... It's real sad to see him go off on a stretcher, but we hope he's OK."

"It's real sad," added receiver Roscoe Parrish, who played with Everett at the University of Miami. "When something like that happens to a close friend of yours, and you know how much he loves football, it bothers you."

Denver players expressed concern, including kicker Jason Elam, who kicked the winning field goal as time ran out.

Before taking questions after the game, Elam, a former University of Hawai'i player, said: "What we heard is not good, so for our whole team, our prayers go out to him."

Buffalo's third-round draft pick in 2005, Everett missed his entire rookie season with a knee injury, and spent most of his second season limited to special teams duty.

The Bills liked Everett's 6-foot-4 frame, and were counting on him to play a role in their passing attack this season.

Buffalo also lost three defensive starters to injury.

Free safety Ko Simpson is out indefinitely after breaking his left ankle. Cornerback Jason Webster is out indefinitely after breaking his forearm in the fourth quarter. Linebacker Coy Wire, who was filling in for injured starter Keith Ellison, sprained his knee in the first quarter.

Simpson was hurt when he had his feet cut out from beneath him by teammate Jason Webster as the two were attempting to tackle Broncos receiver Javon Walker. Simpson fell immediately to the ground and was unable to put any weight on his left foot.

Buffalo's fourth-round pick in the 2006 draft, Simpson started 15 games last season, and was a member of the NFL's youngest safety tandem, playing alongside rookie first-round pick Donte Whitner.

Third-year player Jim Leonhard took over for Simpson.

Wire was examined on the sideline, but made his way to the locker room on his own. Reserve Mario Haggan replaced Wire.