New England Patriots president Jonathan Kraft has revealed that he "doesn't believe" quarterback Tom Brady's injury is serious.

Brady was forced to limp out of his side's training session today after going down clutching the same knee that caused him to miss the entire 2008 season.

The 36-year-old came back on to finish a drill before ending his session prematurely as a precaution. Early reports suggest that the MRI scan on his knee was negative, and Kraft also believes that they shouldn't have much to worry about.

"I understand from people who were standing out here it may have looked serious," Kraft told The Sports Hub.

"I don't have a definitive answer, and in classic [coach] Bill Belichick fashion, I will tell you a little bit more though, and just say I don't believe it's serious, but I do not know."

The Patriots will face the Tampa Bay Buccaneers in a pre-season match on Friday as they continue their preparations for the opening match of the season against the Buffalo Bills on September 8.