The NFL is investigating reports that 11 of the Patriots' 12 allotted game footballs were underinflated by two pounds per square inch.
The Patriots defeated the Colts 45-7 and will face the Seattle Seahawks in the Super Bowl on Feb. 1
“I didn’t alter the ball in any way,” Brady said during a news conference.
“I have a process I go through before every game where I go in and pick the balls — the footballs that I want to use for the game. Our equipment guys do a great job of breaking the balls in. They have a process that they go through.
“When I pick those footballs out, at that point, to me, they’re perfect. I don’t want anyone touching the balls after that, I don’t want anyone rubbing them, putting any air in, taking any air out, to me those balls are perfect and that’s what I expect when I’m on the field.”
Belichick dodges questions
Patriots coach Bill Belichick said earlier Thursday he doesn't know how footballs became deflated during the game that got his team to the Super Bowl.
But Belichick declined to answer questions after saying he knew nothing until Monday morning about accusations that his team cheated with underinflated footballs in its win against the Colts in the AFC championship game.
"I had no knowledge of this situation until Monday morning," said Belichick, who said he was "shocked" to learn the news.
"I would say I've learned a lot more about this process in the last three days than I knew or have talked about it in the last 40 years that I've coached in this league," Belichick said during an 8½-minute opening statement during an 11½-minute news conference. "I had no knowledge of the various steps involved in the game balls and process that went through."
Belichick did not specify who in the Patriots organization was responsible for the underinflated balls, or absolve anyone besides himself of potential wrongdoing.
Softer balls are generally considered easier to throw and catch, and quarterbacks, specialists and equipment managers are known to have individualized preferences in how footballs are readied for games.
Belichick said he sometimes hears quarterbacks, kickers and other specialists talk about their preferences.
"I can tell you and they will tell you that there is never any sympathy from me whatsoever on that subject. Zero," Belichick said.
"Tom's personal preferences on his ball, footballs, are something that he can talk about in much better detail and information than I could possibly provide," Belichick said. "I can tell you that in my entire coaching career I have never talked to any player, staff member about football air pressure."
The NFL requires balls to be inflated between 12.5 and 13.5 pounds per square inch. Under league rules, each team provides 12 balls for use on offence. Referees approve the balls more than two hours before game time, then keep the balls until they're turned over to ball handlers provided by home teams just before kickoff.
Belichick said the balls used by the Patriots offence are inflated to the "12½-pound range" and "any deflation would then take us under that."
In future, he said, the Patriots will inflate footballs to a safe level to prevent them from dropping under allowable air pressure during games.
"We will take steps in the future to make sure that we don't put ourselves in this type of situation again," he said.
The coach, who has won three Super Bowls, said he generally requires players to practise under bad-ball conditions.
"Any time players complain about the quality of the footballs, I make it worse and that stops the complaints," he said. "We never use the condition of the footballs as an excuse. We play with whatever or kick with whatever we have to use."
The issue has drawn strong reaction from around the game and its fans as the Patriots prepare to play the Seattle Seahawks on Feb. 1 in Glendale, Ariz., for the NFL title.
Several players said it would not distract them in preparing for the game.
"It's unfortunate. We'd rather be celebrating our trip to the Super Bowl," special teams captain Matthew Slater said. "It's important to us that we respect the game and deal with things in a way that's considered professional."
Belichick declined to answer several questions after his opening remarks, answering several of them by saying: "I've told you everything I know," and "I don't have an explanation."