Tom Brady declined to confirm whether or not he had a concussion in 2016.
Brady's wife, Gisele Bundchen, had said in May that Brady was concussed last season.
"I don't want to get into things that happened in my past, certainly medical history and so forth. I really don't think that's anybody's business," Brady said after the team's practice at Gillette Stadium. "What happened last year; I'm focused on this year and improving and working on things I need to get better at.
"So that's how I approach everything. I'm not sitting here worried about last year or five years ago. There are other people that do worry about that -- my wife, or my parents, or my sisters, people that love me and care about me. But I do the best I can do to be prepared to play -- mentally and physically -- and I give the game everything I can."
Brady turned 40 this week and was asked whether he's paid attention to recent studies on CTE.
"You're not blind to it as a player. That's why I believe in so much of being proactive with your health," Brady said. "I think when you're a player, and you see other players before you that did things a certain way and what's transpired with their health or well-being, and then you learn from it. I think that's the things I've really tried to incorporate in my own life.
"So I'm confident in what I do. I'm confident in the things I do and the ways I train, you know. But it's a contact sport, and I think we all understand that. There are a lot of great benefits that football brings you, [but] certainly you can be put in harm's way. So you just do the best you can do as a player, and obviously it's great that there is more awareness for those types of things. That's been a very important topic, certainly. But you just try to be proactive and take care of your body the best way you can."