"I'm not a medical person and things change day to day, but we were told that it was as good a report that we could have hoped for," Kraft said at the NFL owners meetings in Boston on Tuesday.
Gronkowski, who broke his forearm last season and re-injured the limb in the playoffs, had metal plates in his arm replaced Monday. Doctors believe that an infection that has lingered this offseason is now cleared, sources told ESPN NFL Insider Adam Schefter.
With back surgery also a possibility, Gronkowski's status for the regular-season opener is still in question, but Kraft was hopeful on Tuesday.
"I hope we have him back for the full season," Kraft said. "I know all the fans want that, and as an owner, I surely do."
The Patriots signed Gronkowski to an extension last summer that could keep him in New England through the 2019 season. With injuries limiting his contributions last season and affecting his preparations for this season, questions have been raised about Gronkowski's durability.
"Part of the parity and the challenge of this business and trying to be good year in and year out and having a [salary] cap, we all have to make decisions with the information we have at hand," Kraft said. "We think long term he still should be great. We'll see."
Prior to his surgery, Gronkowski and Kraft took part in a football clinic Saturday for children in Newtown, Conn., the site of December's school shooting tragedy.
"Gronk was acting like [Tom] Brady and throwing to a bunch of kids. He challenged me to cover one. I thought I did a pretty good job covering, except the young man tripped and Gronk overthrew him," Kraft said. "He was saying it was a penalty on me, [but] the young man fell because Gronk overthrew him and he was trying to catch the ball.
"Once again, Gronk's enthusiasm and exuberance ... he really had the kids going," Kraft said with a smile.