Brady walked off the field under his own power, but was limping on his left knee. He missed one play, returned for a few more, then left for good with head coach Bill Belichick and the team athletic trainer.
This does not sound like anything too serious, but it is never good when your star player goes down on a non-contact play. Former Patriots wide receiver Wes Welker tore his ACL and MCL in 2010 on a non-contact play in Houston.
Sports Illustrated's Greg A. Bedard seems to think the move is more precautionary than anything:
Brady leaving practice after conferring with Belichick and McDaniels. Wise move
— Greg A. Bedard (@GregABedard) August 14, 2013