BOSTON (CBS) –  After a long off-season filled with multiple surgeries, Patriots tight end Rob Gronkowski is on the road to recovery.

According to ESPN’s Ed Werder, Gronkowski has begun his rehab from back surgery with Patriots trainers at Gillette Stadium, focusing on stretching and improving his core strength.

READ MORE: Tufts University Student Dies After Choking On Hot Dog In Charity Event Contest

The All Pro tight end underwent back surgery in June, in addition to a fourth surgery on his broken left forearm. As Werder notes, it’s too soon to know if Gronkowski will be ready to go in Week 1.

“A person who has seen Gronkowski at the facility tells ESPN that Gronkowski looks good and seems to be progressing,” Werder reports, “but nobody yet knows whether he’ll be ready for the Patriots’ opener against the Buffalo Bills.”

READ MORE: Massachusetts Unemployment Rate Up To 5.2%, Slightly Higher Than National Average

The Boston Herald’s Jeff Howe was a guest on 98.5 The Sports Hub’s Toucher & Rich on Wednesday, and said there is a good chance Gronkowski could miss time come the regular season.

Howe On Toucher & Rich: Who Will Catch Passes For the Patriots?

“We’ve been reporting the send of September is the most realistic return date, but I think we’re talking a minimum of 3-4 games,” said Howe. “You have to wonder if the PUP list is a realistic option. He’s going to start Training Camp on the PUP list, so we’ll see if he’s off it (when the regular season begins). If he’s on it, it’s a minimum of six games.”

MORE NEWS: Boston Wine Store Earns 'Small Business Of The Year' Award From US Chamber Of Commerce

“You have to look at the minimum of three, and there’s a very real chance at six (games missed),” said Howe.