Doc Rivers has told acting 76ers head coach Dan Burke that he, Rivers, feels “terrific” while continuing to isolate in health and safety protocols.

Feeling well has allowed Rivers to remain in constant communication with Burke and the rest of the Sixers staff while physically staying away from the team. With Burke in charge, the Sixers’ focus during Sunday evening’s practice included cleaning up execution, experimenting with various lineup combinations and narrowing their package for end-of-game situations.

“My question to him usually is, ‘What are your ‘musts’ tonight? What are [things] we must do?’ Burke said. “And then we go from there.”

Rivers tested positive for COVID-19 Thursday and missed Philly’s impressive 110-102 victory at Brooklyn that night. Last week, the NBA lessened the isolation period from 10 days to six days for vaccinated, asymptomatic players and staffers who are deemed to no longer be infectious to others.

Rivers’ absence comes during a light portion of the schedule. The Sixers did not practice Friday or Saturday, then held their Sunday-evening session to accommodate increased COVID-19 testing. The additional rest offered an opportunity for the Sixers to do some more grueling full-contact work while riding a three-game winning streak ahead of Monday’s home game against Houston.

“A lot of things the league has us doing right now is a little bizarre, but it’s necessary,” Burke said. “We’ve got to get [the work] in when we can. We’re trying to keep this momentum. After the three-game road trip, it’s like you want to play again. We don’t want to wait three or four days.”

Danny Green clears protocols, Matisse Thybulle and Jaden Springer enter

Starting wing Danny Green was back at practice Sunday after clearing health and safety protocols and said he expects to play Monday against the Rockets. Green missed four games after testing positive for the virus and said he had “very slight” symptoms.

“I’ll let you know [how I feel] when we actually get into some type of game-type of atmosphere,” Green said. “It’s probably going to be a little different once I get up and down out there. But today it felt good to practice, [and] yesterday get some workouts in.

“Hopefully tomorrow we’ll all be in pretty good rhythm, in sync, and hopefully I haven’t lost any steps.”

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Green is averaging 7.1 points and 2.8 rebounds per game while shooting 37.4% from three-point distance. He has been limited to 24 games this season while also periodically dealing with hamstring and hip injuries.

Third-year wing Matisse Thybulle, meanwhile, was listed as questionable to play Monday against the Rockets because he had entered health and safety protocols.

Thybulle missed seven games in November after testing positive for the virus. His questionable status could be due to an inconclusive test result. A similar scenario occurred last week with starting point guard Tyrese Maxey, who was listed as questionable heading into a Dec. 26 game at Washington but had been cleared by that morning’s shootaround.

Thybulle is averaging 5.5 points, 2.4 rebounds and 1.8 steals per game and remains one of the NBA’s premier perimeter defenders.

Rookie guard Jaden Springer has also entered protocols, while two-way rookie guard Myles Powell remains out for that same reason.

The only other player listed on Sunday’s Sixers’ injury report was Ben Simmons, who remains out for personal reasons after requesting a trade and feeling mentally unfit to play.

Tyler Johnson’s 10-day contract expires

The Sixers allowed the 10-day hardship contract of veteran guard Tyler Johnson to expire following Thursday’s win at Brooklyn.

Johnson averaged 3.7 points and two rebounds in 12.7 minutes over his three game with the Sixers, but entered health and safety protocols on Thursday.

Philly was able to sign Johnson while multiple players were in protocols in recent weeks, a new rule the NBA adopted to limit game postponements by making sure teams had the mandatory eight players available.