Belichick said Saturday that Brady came out of Friday night's game after a crushing hit from Washington Redskins defensive lineman Albert Haynesworth because it was time for the coaching staff to take a look at the backups. He lumped any problem with Brady's right shoulder into the category of normal "bumps and bruises" from a physical game.
"I'm saying that we made the decision to play other quarterbacks in the Washington game because we wanted them to play," Belichick said in a conference call with reporters.
"Tom had a desire to play, but we made a football decision to play other players because we needed to see them at that position and make an evaluation there. That's what I'm saying," he said.
Brady completed 12-of-19 passes for 150 yards and two touchdowns, hitting Randy Moss six times for 90 yards and both TDs as the Patriots beat the Redskins 27-24 on Stephen Gostkowski's last-minute field goal.
On Brady's last play, he was smashed to the turf by Haynesworth after throwing an incomplete third-down pass just before the first two-minute warning.
Brady was seen on the bench flexing and rotating his right arm, but when the other starters took the field for the first series of the third quarter, the two-time Super Bowl MVP was not among them. He then left the sideline and returned to the locker room.
The team announced that he had a sore right shoulder.
Brady did not speak to reporters after the game.
Belichick said Saturday that he didn't have anything to add.
Asked whether Brady had an X-ray, Belichick said, "I'm not really comfortable getting into a public diagnosis."
"We played a physical game against a really physical team," he said. "I'm sure after the game there were a lot of guys who had bumps and bruises. That's pretty normal after a game like that."
Asked if Brady would be listed as "probable" if the regular-season opener was next week, Belichick said, "We'll fill that report out when it comes. That's happened before."
Belichick once listed Brady "probable" with a sore shoulder on injury reports for several years in a row, a practice that angered opponents and led the NFL to change its injury report procedures. The NFL's current media policy says: "Clubs must ensure that all medical information issued to the media is credible, responsible and specific in terms that are meaningful to teams, media and fans."
Asked whether "sore shoulder" was specific enough to describe the injury, NFL spokesman Greg Aiello said: "That is credible and specific information in compliance with our policy."
Brady missed most of last season after he was injured in the opener and had surgery to repair the ligaments in his left knee. His health could be the sole difference between whether the Patriots are Super Bowl contenders, like they were when he led them to a 16-0 record in 2007, or playoff also-rans, like they were without him last season.
"You just know it's part of the game, and Tom's been through it before," offensive lineman Matt Light said Friday, "and you know he can take it."