"Probably underrated. He doesn't really sometimes come across in that role but what I see, Rob's very attentive, very coachable," Belichick said Wednesday.
"You tell him what you want him to do, he works very hard to do it the way you want it done. He's a smart football player.
"He understands leverage, he understands position, he understands technique. He understands the concept of what you're trying to do. We move him around at lot of different positions. He has a really a lot to learn."
Asked why, Belichick said, "Probably other than the quarterback, the tight end position on our offense is the hardest to play because you have all the protections, all the running game and you have routes from sideline to the middle of the field to occasionally even in the backfield. There's really no plays off mentally for that position.
"His work ethic, his ability to work with his teammates, whether it's the quarterback, the offensive tackles, the other tight ends or even with the defensive players is good. He's really a great guy to have on the team. Forget about the talent and all that. Just the way he goes about his job, the way he works, trains in the weight room, his physical conditioning, his mental concentration and focus and desire to be well and do well and improve are very, very good.
"I think Rob's always been an accountable player."
Quarterback Tom Brady agreed with his coach.
"Just what his mental toughness has been, as an athlete, what he's overcome the last few years, with his arm, his back and then his knee," said Brady, who has thrown 57 touchdown passes to Gronkowski, the pair trailing only the Philip Rivers to Antonio Gates 72 connections between a QB and tight end.
"I just think he sets a great example for our team — the work ethic, he's a fun guy to be around.
"Ultimately he goes out and performs (the) best as he possible can and he does it with toughness, no matter what he's asked to do, whether it's in the run game ... obviously he gets a lot of attention for catching touchdown passes, but he does all the dirty work, too. He's in there blocking for the backs, and pass protection and takes a lot of pride in all those things."
Gronkowski has caught four touchdown passes in the first two games and has at least one in the past five regular-season games. A TD grab Sunday against Jacksonville would allow him to equal his career high of six straight games.
He is already well on pace to becoming the first tight end in NFL history with three seasons of 1,000 yards (he's at 207) and double-digit touchdown catches.
"He's been out there every day this year practicing as hard as he can," Brady said. "I think it's just shown a huge commitment by him really to all of us players of what it means to him — and I think he's been a great example to all of us."
Asked if this is the best Gronkowski has been in his career, Brady said, "He's always been a pretty spectacular player, going back to his rookie season. He's played at such a high level and has been so consistent. I don't think we expect anything less of him now."
NOTES: Brady's next touchdown pass will make him the fourth quarterback with 400. Peyton Manning leads with 533, Brett Favre had 508 and Dan Marino 420. ... Despite the 2-0 start, Belichick says his team has work to do to improve. "We definitely have a lot to improve and that has been clearly emphasized," said offensive tackle Nate Solder. ... OL Ryan Wendell, who hasn't played yet this season because of an illness, continued to be missing from practice.