Kemba Walker taking it slow as knee continues to mend

Celtics players huddled during practice on Wednesday at an empty TD Garden.Boston Celtics (Custom credit)

Celtics point guard Kemba Walker, who was put on a 12-week strengthening program after receiving a stem-cell injection in his left knee in early October, has started doing some light shooting drills.

Coach Brad Stevens said Saturday that Walker is mostly taking spot-up jump shots with limited movement, and he has yet to participate in group work with the rest of the team.

“I’m going to learn more in early January about real timelines,” Stevens said. “I’m guessing like everything else, he’ll probably progress to the next stage fairly quickly. Next stage might be like being involved in a four-person group work where you’re doing some simulated defensive drills or simulated offensive reads, oftentimes not going full speed.”

Walker dealt with consistent left knee soreness last season. He missed six games in February after having the knee drained, and his playing time was limited during the regular-season portion of the Orlando restart before being ramped up considerably during the playoffs. The quick turnaround this season presented new challenges, and the Celtics have made it clear they will proceed with caution.

Stevens said that center Tristan Thompson, who suffered a mild hamstring strain prior to training camp, has done some very light two-on-two and three-on-three work before practices over the last week but has yet to take part in a full session.

Last season Thompson played for the Cavaliers, one of the eight teams that did not take part in the Orlando bubble, so he has not played in an NBA game since last March.

“There will be a ramp-up period for him whenever he is able to go live in practice, and I’m assuming it won’t be one of those situations where you’re available one day and you get a good practice in and you can play,” Stevens said. “I think it’ll be a little more than that. I don’t know what that means with regard to [the season-opener vs. Milwaukee] Dec. 23. Every day that passes I’d say that becomes more unlikely.”

Lastly, Stevens said, rookie guard Payton Pritchard dislocated a finger on his non-shooting hand during Saturday’s practice.

“They were able to place it back and hopefully his timeline to return to practice will be sooner rather than later, on his left hand,” Stevens said. “But I think everybody else has been good to go.”

The Celtics face the 76ers in a preseason game on Tuesday night.

Rosters expanded

The Athletic reported Saturday that the NBA’s competition committee unanimously voted to expand active rosters on game days from 13 to 15. The NBA’s board of governors is expected to vote on the measure this week, and it is likely to be approved.

Stevens said he was in favor of the change.

“I think in this situation and moving forward it just makes sense,” he said. “If somebody’s healthy — very rarely are you going to have more than 15 that are available, and so it rewards everybody that’s available with a chance to dress and ultimately play. I think that’s good. I’m a big fan of that move.”

Short learning curve

The Celtics played in the Eastern Conference finals in late September and did not have much roster turnover, so they could be equipped to handle the abbreviated training camp better than most teams. But there is still a learning curve for some players, such as veteran additions Thompson and Jeff Teague.

“It’s a little difficult, because we can’t spend as much time together because of certain rules,” Teague said. “It’s going fast, and we don’t have as much time to jell as we would in a normal offseason. Usually guys come in, play pickup and things like that, and you get to know someone on and off the court. Right now it’s a crash course. The good thing about this team is they have a really good nucleus, and I’m just trying to fit in and figure it all out.”