Tom Brady
Tom Brady is still going strong despite turning 41 last month. In this picture, Brady #12 of the New England Patriots looks on against the Carolina Panthers in the second quarter during their game at Bank of America Stadium in Charlotte, North Carolina, Aug. 24, 2018. Streeter Lecka/Getty Images

As he prepares the Houston Texans to face the New England Patriots for the start of the new NFL season, head coach Bill O'Brien only had praise for Tom Brady and his longevity in the sport.

Brady will enter his 19th season this year and having turned 41 last month, is still going strong, especially as he was named regular season MVP in the 2017 season, though he could not extend his record of five Super Bowl wins earlier this year.

The quarterback is very particular with his fitness regime, the TB12 Method, customized to get the best out of himself as he continues to get older. Alex Guerrero, his body coach and business partner, plays a big role in that department.

And O'Brien, formerly with the Patriots as an offensive coordinator, believes Brady is only continuing to improve as he praised the latter's longevity.

"Yeah, I think that — you know, first of all, people talk about the later parts of his career. I don’t really see where his — you know, I don’t know when his career’s going to be over because he’s playing at a — I mean, he was the MVP last year, you know what I mean?" O’Brien said in a conference call Tuesday. "So, like when is his — I don’t even know what the definition of latter part of this guy’s career would be."

"He’s the MVP of the league last year. So, I think that with every veteran player that’s lasted over 10 to 15 years in our league, whatever position they play, they always find a way to take care of their bodies in different ways. You know, every guy does it in different ways and they find a way to keep their legs in shape, to keep their upper bodies in shape, to keep their minds sharp relative to the game and obviously Tom [Brady] does a great job of that," he added.

Brady is regarded by many as the greatest quarterback of all time, and his success over the years has led to him being abhorred outside New England.

But more than his ability, O'Brien is also impressed with Brady's work ethic and his strive to get even better.

"I think this guy is a great football player, he works so hard at all the different parts of his game relative to mechanics and knowledge of the game, knowledge of his teammates," O’Brien added. "He’s always working at it."

"I can remember when I was there [with the Patriots], phone calls in the offseason, you know, ‘What’s happening here? Hey, I was thinking about this.’ You know, always thinking about football and how to get the edge and that’s why he’s the player he is and he’s had the career that he’s had and that’s why he’s still playing. Because he’s found that edge and he continues to try to get better every single day," he said.

The Patriots will host the Texans on Sunday at the Gilette Stadium in Foxborough, Massachusetts.