Tom Brady limped off the field in pain, and the New England Patriots can only hope their Super Bowl hopes didn't go with him. The NFL's reigning MVP left Sunday's 17-10 victory over Kansas City midway through the first quarter with an injured left knee after being hit on a throw. There was no immediate word on the extent of Brady's injury _ "I am not sure what we are dealing with," coach Bill Belichick said _ or how long he would be out.

"It kind of looked bad," wide receiver Randy Moss said.

Various reports Sunday night said Belichick told the players that the injury was serious. The Patriots were already looking for a possible replacement for Brady. A person familiar with the situation told The Associated Press that former Tampa Bay quarterback Chris Simms was coming in Monday for a physical.

Brady went to the locker room and wasn't seen again as backup Matt Cassel led the Patriots to the victory. Cassel, who had thrown just 39 passes in his first three seasons, could see a lot more action if Brady is sidelined next week _ or beyond.

"They're looking at him, doing some tests on him, so I don't have any information there," Belichick said, cracking a smile as he added, "doubt anybody's interested."

The 31-year-old Brady, who last season led the Patriots to an undefeated regular season and their fourth Super Bowl in eight years, wasn't available for comment after the game.

"He's the face of the New England Patriots, and Tom being who he is, it kind of hurts, to be honest with you," said Moss, who caught a record 23 TD passes from Brady last season.

In other games, it was Tennessee 17, Jacksonville 10; the New York Jets 20, Miami 14; Carolina 26, San Diego 24; Chicago 29, Indianapolis 13; Dallas 28, Cleveland 10; Arizona 23, San Francisco 13; Pittsburgh 38, Houston 17; Philadelphia 38, St. Louis 3; New Orleans 24, Tampa Bay 20; Atlanta 34, Detroit 21; Buffalo 34, Seattle 10; and Baltimore 17, Cincinnati 10.

On Monday night, Minnesota is at Green Bay and Denver is at Oakland.

At Foxborough, Mass., Brady, who has started 128 consecutive games, went to the turf clutching his left knee midway through the first quarter. After being tended to on the field, he walked off, limping, between two trainers.

After missing the entire preseason with an unspecified foot injury, Brady was hit on the left leg by Chiefs safety Bernard Pollard.

"He was in a lot of pain," Pollard said. "When you hear a scream, you know that."

The Patriots plummeted from an exclamation point of an unbeaten 2007 regular season to a huge question mark to begin 2008. They lost the Super Bowl to the New York Giants 17-14, then went 0-4 in the exhibition season while Brady had a right foot injury and missed all four games.

Cassel went 13-for-18 for 152 yards and one touchdown.

"This is something I've been preparing for (for) a long time. It's not something that we expected to come up on opening day," Cassel said. "Since I've been here and been around Tom, he's always popped back up."

Not this time. And Kansas City also had its own quarterback woes.

Damon Huard took over for the Chiefs after Brodie Croyle left with a bruised shoulder late in the third quarter.

Titans 17, Jaguars 10

The Titans also aren't sure if they'll be without their quarterback for any time. Vince Young was on crutches at Nashville after spraining his left knee late in their win.

Tennessee coach Jeff Fisher said his quarterback will have tests to determine the severity of the injury, but added that Young's knee appeared to ease up in the locker room.

"The biggest concern that I have right now, not knowing, I don't think it is serious about Vince," Fisher said. "We are going to do some studies, some tests on his knee."

The Titans sacked David Garrard seven times and Cortland Finnegan intercepted him twice in the season opener between the AFC's two wild cards in 2007.

Jacksonville came in without top backup Richard Collier on the offensive line after he was shot earlier this week. The Jaguars had three more linemen get hurt, and Maurice Williams and Vince Manuwai didn't return. That helped Tennessee limit the Jaguars to 187 yards offense, just 33 yards rushing by what was the NFL's second-best rushing team last season.

Jets 20, Dolphins 14

At Miami, Brett Favre made a successful debut, throwing for two touchdowns six months after calling it a career in Green Bay before changing his mind.

Favre's new start with the Jets had a happy ending thanks to two late stands by New York's defense. Dwight Lowery batted away a fourth-down pass in the end zone with 9 minutes left, and Darrelle Revis intercepted Chad Pennington _ again in the end zone _ with 5 seconds left.

Favre finished 15-for-22 for 194 yards and his 161st victory, extending his NFL record for starting quarterbacks.

Pennington, the man Favre replaced, was 26-for-43 for 251 yards and two TDs for Miami.

Panthers 26, Chargers 24

Panthers quarterback Jake Delhomme threw a 14-yard touchdown pass to Dante Rosario as time expired in San Diego, capping a desperation drive for the win.

After Philip Rivers rallied San Diego with his third TD pass of the game, Delhomme moved the Panthers to the San Diego 14 with 2 seconds left before calling his final timeout. Delhomme dropped back on fourth down and found Rosario in the back of the end zone.

Delhomme returned after missing all but three games last season with an elbow injury that required reconstructive surgery. He was 8-of-11 for 68 yards on the final drive.

Cowboys 28, Browns 10

Terrell Owens caught a 35-yard touchdown pass, Tony Romo picked apart Cleveland's secondary, and Marion Barber scored on a pair of 1-yard runs for the Cowboys.

With Romo completing 24 of 32 passes for 320 yards, Dallas' offense controlled the clock and strung together four long touchdown drives at Cleveland.

Bears 29, Colts 13

Matt Forte ran for 123 yards and one touchdown in his NFL debut, and Kyle Orton committed no turnovers to help Chicago beat Indianapolis in the first regular-season game at Lucas Oil Stadium.

Two-time league MVP Peyton Manning didn't look like himself in his first game since having surgery to remove an infected bursa sac from his left knee in July. He went 30-of-49 for 257 yards with one TD.

The loss snapped the Colts' 21-game winning streak in September and October, the longest run since Green Bay won 23 straight pre-November games from 1928-32.

Cardinals 23, 49ers 13

At San Francisco, Kurt Warner passed for 197 yards and led three monotonously effective drives in the second half for Arizona. Anquan Boldin had all of his eight catches for 82 yards in the second half of the Cardinals' third straight opener against the 49ers, who beat them twice last year to ruin their playoff hopes.

J.T. O'Sullivan passed for 195 yards in his first NFL start for the 49ers. Frank Gore rushed for 96 yards and San Francisco's only touchdown on an early 41-yard scamper, but the Niners' offense barely got on the field in the second half.

Steelers 38, Texans 17

At Pittsburgh, Willie Parker ran for 138 yards and three touchdowns and a near-perfect Ben Roethlisberger threw two scoring passes to Hines Ward in a rout that began with Houston's fourth-down failure on its opening possession.

The Steelers have won six straight consecutive season openers, the NFL's longest since Miami won 11 in a row from 1992-2002.

Eagles 38, Rams 3

Donovan McNabb threw for 361 yards and three touchdowns, and rookie DeSean Jackson had an impressive debut at Philadelphia.

McNabb was 21-for-33, including a 90-yard TD pass to Hank Baskett. Jackson, the first Eagles rookie wide receiver to start a season opener in 18 years, had six catches for 106 yards and returned a punt 60 yards to set up a field goal.

Saints 24, Buccaneers 20

At New Orleans, Drew Brees passed for 343 yards and three touchdowns, giving fans already jubilant about the Saints' quick return from Hurricane Gustav a triumph to celebrate as well.

Tampa Bay had a shot to win the brutally physical, back-and-forth contest until Scott Fujita intercepted Jeff Garcia's fourth-down pass just inside the Saints 20 with less than 40 seconds to go.

Falcons 34, Lions 21

Matt Ryan threw for a touchdown on his first NFL pass, and Michael Turner set a team rushing record with 220 yards and two TDs in his Atlanta debut.

The Falcons scored on their first three possessions for a 21-0 lead. Ryan, the third overall selection in the draft, completed his first five passes and finished a workmanlike 9-for-13 for 161 yards.

Bills 34, Seahawks 10

At Orchard Park, N.Y., Roscoe Parrish scored on a 63-yard punt return, and punter Brian Moorman completed a 19-yard touchdown pass to defensive end Ryan Denney on a fake field goal, sparking Buffalo to a dominating win.

As if that wasn't enough, kicker Rian Lindell recovered a fumble on a kickoff, setting up Trent Edwards' 30-yard touchdown pass to Robert Royal.

Marshawn Lynch also scored on a 21-yard run as the Bills opened a season with a win for only the fourth time in 12 years.

Ravens 17, Bengals 10

At Baltimore, the Ravens forced two turnovers and limited the Bengals to 154 yards to make John Harbaugh a winner in his debut as an NFL coach.

Cincinnati's Carson Palmer was 10-for-25 for 99 yards, and his interception ended the Bengals' deepest foray into Baltimore territory _ except for a 65-yard fumble return for a touchdown by Johnathan Joseph.

Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.