The wide receiver ended his six-year stint with the Patriots earlier this year, signing a two-season deal with the Denver Broncos.
The 32-year-old told Sports Illustrated: "It was just kind of hard, one of those deals where you have to endure him, put up with him, but he does it to everybody, it's the way he is.
"When I'm answering questions from the Denver media, I'm not worried about what the Broncos' people are going to think. I'm worried about what Belichick will think. Isn't that crazy?
"He was very intense, wanted it done a certain way and was like, You can't do it a different way."
Welker will face his former team during the 12th week of the 2013 season.