Gronkowski underwent surgeries on his back and forearm during the off-season and is yet to feature for the Patriots so far this season as he continues his rehabilitation.
The 24-year-old insists that he is edging closer to a return by taking his recovery day-by-day but would not put a time frame on when he would be back by.
"I'm progressing every week, I'm feeling better every week, getting stronger every week and better conditioning every week. Just still sticking to the motto 'day by day,'" Gronkowski is quoted as saying by ESPN.
"Everything's great around here. Just going out to practice with the team and practising with the team, it's helpful every single week to get the chemistry back down and get the timing of football back down.
"When I'm ready, I'm ready. If it's this Sunday, next Sunday, the Sunday after that, it's just going day-by-day. So I really couldn't tell you when it's going to be. I would say that it's the best I've felt and that's because from working harder each week. I'm progressing every week."
The Patriots have made a fine start to the season without Gronkowski, winning their opening four games going into Sunday's match against the Cincinnati Bengals.