FORT COLLINS, Colo. -- Philadelphia 76ers coach Nick Nurse said James Harden fully participated in Friday's final training camp practice at Colorado State University, marking the first time Harden had gone through all of practice since rejoining the team Tuesday evening.

What's next for Harden, though, remains unclear. Friday afternoon, the 76ers are flying straight from Fort Collins to Boston, where they will open the preseason Sunday night against the Celtics (6 p.m. ET, ESPN), and Nurse said Harden, along with several of his teammates, are still ramping up their activity levels, making it uncertain who will be taking part.

"I do not know," Nurse said when asked whether Harden will play Sunday in Boston. "I think that we still got a number of people that we're trying to kind of ramp up to get to Sunday, so I don't know how that'll go yet. We certainly got another day [of practice in Boston] tomorrow, and I think tomorrow will be a hard-working, physical day. It's training camp, so you don't really kind of pare down going into that stuff. We're still into getting after it and competing tomorrow, so have to see how everybody comes out after that and see where we are."

Harden, who has yet to speak to reporters since returning to practice, was on the court for an extended shooting session with fellow guard Tyrese Maxey after Friday's practice -- also a first after largely being out of sight of the media each of the past two days.

Nurse admitted that, across the board, he still doesn't have a feel for how things will look Sunday against Boston.

"I'll probably push some lineups and rotations around a little bit on the flight here this afternoon," he said. "I think all that stuff's just a little bit fluid. Again, see how everybody comes out of [practice] tomorrow. Usually at this time, especially the first game, it's just kind of where they are, a lot of communication with them, how they're feeling. Some guys want the minutes to get to for conditioning. Some guys just want to kind of get started on the minutes and some guys won't be ready. So, a little bit of everything."

Friday, however, marked a third straight drama-free day for Harden and the 76ers, with things feeling almost normal since Harden first returned to the court Wednesday.

But this situation is anything but normal. Harden requested a trade back in June after picking up his $35.6 million player option for this season, then publicly called Daryl Morey -- the team's president of basketball operations and someone Harden has been aligned with since Morey traded for him 11 years ago while running the Houston Rockets -- a liar at a shoe event in China in August.

He missed media day at the team's facility in Camden, New Jersey, and then the opening practice at Colorado State, only to take part in the past three days without incident.

As the 76ers left Colorado State on Friday, they felt good about where things stood after their opening few days of practice together.

"It's cool. Good energy. Another training camp," P.J. Tucker said. "Camp's always fun, interesting. ... Young guys bring energy, old guys kind of get back started, get going, get around each other. But we had a good time. It was good."