"[He's] having some of the post-surgery challenges of pain and everything else," said Stevens. "But the surgery went great. His spirits were pretty positive.
"We talked a little bit about how to approach the next five months with maintaining that positivity -- different ways to stay engaged, different ways to approach this, to attack this, and he was ready to get started on his rehab the minute he got out of surgery."
Stevens said Hayward was released from New England Baptist Hospital on Friday.
Celtics fans will perk up at the reference to "five months," which potentially hints that Hayward might be in position to resume basketball-related activities by late March. The Celtics have emphasized that there is no immediate timetable for Hayward's return to action, and his agent, Mark Bartelstein, has told ESPN that it is unlikely that Hayward will play this season.
Hayward was injured in the first quarter of the season opener in Cleveland on Tuesday night. An All-Star for the Utah Jazz last season, Hayward joined the Celtics this summer as a free agent.
Stevens seems eager to find ways to help Hayward maximize his time on the sideline. Stevens even reached out to Frank Vogel this week for advice on how to keep Hayward engaged during his recovery. Vogel was head coach of the Indiana Pacers while Paul George recovered from a horrific leg injury. Stevens, who previously coached at Butler University, is friends with Vogel from their shared time in Indianapolis.
"It's easy to kinda hole up when you're going to be out a long time," Stevens said. "You're excited because you anticipate a full recovery, but I think it's really important to just be active, and to be as active as you can.
"I called Frank Vogel the day I drove to the gym, when we played Milwaukee, and just asked him, 'What are some of the things that Paul did in his year off that you would really encourage? What are some of the things that we should be looking [to]?' And, hey, [Hayward is] going to be the best guy shooting out of a chair, with his left hand, with his right hand, perfect his form, and let's have fun. Let's come up with creative ways to attack this thing."
The Celtics are 0-2 and are expecting a challenge Friday night as Philadelphia hosts its home opener. Stevens said he hasn't thought much about potential roster additions as the Celtics operate short-handed after the loss of Hayward.
Said Stevens: "My sole focus has been on Gordon and trying to make sure that we maximize this group that we have right now."