Tom Brady makes one of his first and last passes of the season [GALLO/GETTY]

Brady, 31, was hurt during the first quarter of the 17-10 season-opening victory over the Kansas City Chiefs when he stepped up into the pocket and was hit by safety Bernard Pollard.

"We feel badly for Tom about the injury," coach Bill Belichick said.

"You hate to see anyone go down. Nobody's worked harder or done more for this team than Tom has. So it's a tough setback for him."

Second scan

Belichick said he did not know what a second MRI on Brady's knee had revealed. A team statement on Monday did not specify the nature of the injury.

"After extensive tests this morning, it was revealed that New England Patriots quarterback Tom Brady's left knee, which was injured in the first quarter of yesterday's game, will require surgery," the statement said.

"He will be placed on injured reserve and will miss the remainder of the 2008 season."

The Patriots, who have won three NFL championships with Brady at the helm, were undefeated last season until the Super Bowl when they lost 17-14 to the New York Giants.

In at the deep end

Brady was replaced against the Chiefs on Sunday by Matt Cassell, a seldom-used quarterback who has not started a game since high school.

Cassell, 26, completed 13 of 18 passes for 152 yards and one touchdown. New England will visit the New York Jets and Brett Favre this weekend.

"Each guy has a job to do - a coach, a player - they have a job to do and they need to do it as well as they can," said Belichick.

"That doesn't change. He (Brady) played one position and played it very well. It will be somebody else playing that position now. I have a lot of confidence in Matt."