"I'm glad that Rob's optimistic about his situation," Belichick told reporters, according to Josh Katzowitz of CBSSports.com. "With all due respect to Rob, I'm glad he feels the way he does, but in the end, we'll have to make the decision that we feel is best for the team and we'll do that as we go through the week."
Gronkowski, 25, underwent surgery for a torn right ACL on Jan. 9. He did not play in the preseason.
Gronkowski has 3,255 receiving yards and 42 touchdowns in 50 regular season games over four seasons. He said on Monday he wouldn't play every offensive snap, but just wants to "get my feet wet."
"A player hasn't played in preseason, there's still game speed and game situations and all the communication that goes on in the game," Belichick said. "That's just different in practice. You have to be ready to handle that and work with your teammates in those conditions and that kind of timeframe and those type of game situations that change so fluidly. ... Your mind has to transfer situations and transfer them very quickly because every play takes on a new down and distance or possibly field position.
"Players that aren't in the game need to be able to have that time on the sideline to make adjustments and be ready to anticipate things that are going to happen the next series and all that. You don't get good at those things with your teammates without being able to do them. It takes some time. Guys that don't play have to make that ground up."
- Chris Mascaro