KANSAS CITY, Mo. — Members of the Kansas City Chiefs angrily spoke out Sunday against thousands of fans who cheered when quarterback Matt Cassel left a 9-6 loss to the Baltimore Ravens with a head injury.

Cassel has been the focus of frustrated fans for the past couple years, many of them booing him when he appeared during a celebrity softball game this summer. Some had even hired an airplane to fly over Arrowhead Stadium on Sunday with a banner asking for him to be benched.

The angst reached a tipping point when Cassel, who committed four turnovers against Baltimore, was hammered by the Ravens' Haloti Ngata while completing a pass in the fourth quarter.

Cassel remained on his back for several minutes while fans began to cheer. He eventually got to his feet with some help and walked off the field under his own power.

"It's 100-percent sickening," Chiefs tackle Eric Winston said. "I've never, ever — and I've been in some rough times on some rough teams — I've never been more embarrassed in my life to play football than at that moment right there. I get emotional about it because these guys, they work their butts off. Matt Cassel hasn't done anything to you people.

"Hey, if he's not the best quarterback, he's not the best quarterback, and that's OK, but he's a person," Winston continued, the big offensive lineman's voice slowly rising. "And he got knocked out in a game and we've got 70,000 people cheering that he got knocked out."

The Chiefs have only said that Cassel has a "head injury," and coach Romeo Crennel said he wasn't sure whether he'd been taken to a hospital. Brady Quinn finished the game.

"We are not gladiators and this is not the Roman Colosseum. This is a game," said Winston, who spoke to Cassel briefly in the locker room after the game. "This is a game that's going to cost us a lot down the road. That's OK. We picked it. We deserve it. I don't want your pity. But we've got a lot of problems as a society if people think that's OK."

Cassel was intercepted twice by the Ravens, though both passes were tipped. He was also hit with two lost fumbles, one of them on a pitch that was mishandled by running back Cyrus Gray and the other on a flubbed exchange with Kansas City facing first-and-goal at the Baltimore 1.

"It's not right, you know what I'm saying? I'll speak that for any stadium, any player to get hurt," said Chiefs running back Jamaal Charles, who missed most of last season with a torn ACL.

"When someone gets booed, it's not right. It's his health. You know what I'm saying? He got hurt. You have to respect," Charles said. "It wasn't right that he got booed."

Once a Pro Bowl quarterback, Cassel is completing just 58.5 percent of his passes with five touchdowns and nine interceptions. He's averaging just 6.5 yards per pass attempt.

"I knew I hit him hard, but I didn't think it was hard enough to take him out. I thought I hit him right in the ribs," Ngata said. "Hopefully, he bounces back and gets better."

As for the cheering? Even the Ravens thought it uncouth.

"For them to cheer for him being hurt," Ngata said, "that's just not cool."