Chiefs quarterback Matt Cassel could be lost for the season with what his coach calls a significant injury to his throwing hand.

Coach Todd Haley refused to say Monday whether the team had discussed putting Cassel on injured reserve, but he did say “it’s a possibility” when asked whether Cassel would be done for the year.

“He will probably have to have surgery at some time,” Haley said. “The length of it, we’re not sure, but there’s some optimism. Each person it varies, but it’s a difficult injury.”

The Chiefs have already lost All-Pro running back Jamaal Charles, Pro Bowl safety Eric Berry, tight end Tony Moeaki and linebacker Brandon Siler to season-ending injuries.

Cassel hurt his right hand near the end of the Chiefs’ 17-10 loss to Denver on Sunday. The injury appeared to occur when Cassel was sacked by Elvis Dumervil and Von Miller, though Haley wasn’t sure if it was the hit or the way Cassel landed on the turf that caused it.

“This has been a fluid situation,” Haley said.

Tyler Palko played the final offensive series against Denver, leading the Chiefs to a field goal, even though Cassel said after the game that he wanted to play.

“I was a little banged up, so that’s what kept me out,” Cassel said, adding that he thought he’d be OK to play at New England next Monday night. “I wanted to go but I was told not to.”

The injury turned out to be more severe than anyone expected.

Palko was informed by quarterbacks coach Jim Zorn on Monday that he’ll likely get his first NFL start against the Patriots. Fifth-round draft choice Ricky Stanzi, who has been inactive all season, will become the backup, though Kansas City could sign a veteran free agent for some depth.

“I’m really close with Matt and we’ve been through a lot these last two years,” Palko said in the Chiefs’ mostly empty locker room Monday afternoon. “You hate to see anybody go down like this, but it’s football, and you just have to be ready.”

The Chiefs (4-5) are in a three-way tie with San Diego and Denver, all chasing the AFC West-leading Oakland Raiders (5-4). The Chiefs, however, have dropped two frustrating games in a row — 31-3 to the then-winless Dolphins and Sunday to the Broncos, both at Arrowhead Stadium.

It hasn’t helped that the Chiefs are missing several of their best players.

Siler went down in training camp with a torn Achilles tendon, not long after signing with Kansas City. Moeaki tore his left ACL in the Chiefs’ preseason finale, Berry sustained the same injury in the first quarter Week 1 against Buffalo, and Charles tore his left ACL early in Week 2 at Detroit.

“It’s crazy, man, just the game, the NFL, how the season is going,” fullback Le’Ron McClain said. “Whoever is next to step in has to step in and play, because the season’s going to continue.”

It’s not going to get any easier, either.

The Chiefs’ game at New England on Monday night starts perhaps the most grueling stretch any team will face this season. They return home to play Pittsburgh, and then visit Chicago and the New York Jets, before playing host to the Super Bowl champion Green Bay Packers on Dec. 18.

It’s unclear whether Cassel will be available for any of those games.

Cassel, who signed a six-year, $63 million deal before the 2009 season, has struggled mightily all year, hurting his ribs early on and never quite playing up to the level he did last season.

He’s completing just 59.5 percent of his passes for 1,713 yards, with 10 touchdowns and nine interceptions. His quarterback rating of 76.6 is nearly 20 points below his rating last season, when he led the rebuilding Chiefs to a surprise AFC West championship.

Cassel was just 13 of 28 for 96 yards and a touchdown against Denver. He was sacked four times, one week after getting dropped five times, and spent most of the afternoon running away from the Broncos’ pass rush. Kansas City managed just 258 yards of total offense in the game.

A good chunk of that came when Palko came on for the Chiefs’ final series.

The journeyman quarterback signed with New Orleans as an undrafted free agent out of Pitt in 2007, and spent some time with the Arizona Cardinals and Pittsburgh Steelers, along with playing in the CFL. He signed with the Chiefs last year and did enough to earn the backup job this season.

The son of a high school coach, Palko has only appeared in four regular-season NFL games.

“Tyler is the next in line, and he’s done a terrific job, like I said, of keeping himself ready,” Haley said. “That’s what the No. 2 quarterback has to do, because you don’t know. At a moment’s notice, you could be in there playing, just like any other position.”

— Associated Press —