Brady, who was lost for the season in 2008 when he suffered a knee injury in the first week of the campaign, was hit during a workout session with members of the Tampa Bay Buccaneers.
Sources told NFL.com that more tests would be conducted, but that did not appear to be any structural damage to the knee.
The Tampa Bay Times reported that Buccaneers defensive end Adrian Clayborn pushed New England offensive tackle Nate Solder back into Brady, causing the injury.
Brady has been selected to the Pro Bowl eight times in his 13 seasons.
He has completed 3,798-of-5,958 passes (63.7 percent) for 44,806 yards and 334 touchdowns. The number of passing touchdowns is fifth-most all-time in the NFL and the yardage total is ninth-highest in league history.