Rob Gronkowski says he hasn't spent any NFL contract money

Rob Gronkowski certainly is one to enjoy himself, but the New England Patriots tight end refuses to break the bank to do so.

In fact, he says in his new book "It's Good to be Gronk" that he's yet to spend any of the money that he's made from the Patriots over his five NFL seasons -- which amounts to more than $10 million.

Instead, Gronk is living off his endorsement deals. And yes, he's having a good time doing so.

"To this day, I still haven't touched one dime of my signing bonus or NFL contract money," Gronkowski says in an excerpt of his book, which was authored by agent Jason Rosenhaus and previewed on TheMMQB.com on Monday. "I live off my marketing money and haven't blown it on any big-money expensive cars, expensive jewelry or tattoos and still wear my favorite pair of jeans from high school.

"I don't hurt anyone. ... I don't do drugs, I don't drive drunk, I don't break the law. ... [I'm] just looking to have a fun time."

The book also details how Patriots coach Bill Belichick asked Gronkowski in 2013 about his lifestyle:

"Coach Belichick was standing right next to me and said, 'Rob, you are one of the hardest workers I've seen, and you're always working hard when you're here, but when you're not here ... I don't know about your craziness off the field, the messing.'

"I started laughing and told him, 'The fun stuff makes me grind harder, Coach.' He shook his head as he walked off and said, 'Whatever works for you.'"