"I have no explanation for what happened," New England Patriots coach Bill Belichick said Thursday morning when addressing the media on the "Deflategate" controversy.
"We have cooperated fully, quickly and completely," with the NFL's investigation, he said.
The league is looking into a report that claimed the New England Patriots used under-inflated footballs in Sunday's AFC Championship Game against the Indianapolis Colts.
The NFL says its investigation is ongoing.
"When I came in Monday morning, I was shocked to learn of the news reports about the footballs," Belichick said. "I had no knowledge whatsoever of this situation until Monday morning. I would say I've learned a lot more about this process in the last three days than I knew or have talked about in the last 40 years that I have coached in this league.
"In my entire coaching career, I have never talked to any player or staff member on football air pressure," he added. "To me, the footballs are approved by league and game officials pre-game and we play with what's out there."
The Patriots will take on the Seattle Seahawks in Super Bowl XLIX in Glendale, Arizona, on Sunday, Feb. 1.
"I'm trying to coach the team, and that's what I want to do," Belichick said.
The NFL began looking into the issue not only because doctoring the footballs could provide a competitive advantage, but because it would compromise the integrity of the game.
Deflating a football can change the way it's gripped by a player, or the way it travels through the air.
Under NFL rules, each team provides balls each game for use when its offense is on the field. The balls are inspected before the game by the officiating crew, then handled during the game by personnel provided by the home team.
Belichick said in the future, the Patriots will be sure to inflate footballs over the minimium 12.5-pounds per square inch to account for any possible change during the game.
"It's unfortunate that this is a story coming off of two great playoff victories by our football team and our players," Belichick said. "But again, we've been cooperative with the NFL investigation. We'll continue to do so and we will turn all our attention and focus on to the Seattle Seahawks, a very well coached, talented, tough, competitive football team."
Patriots quarterback Tom Brady is scheduled to address the media around 3:45 on Thursday afternoon.