Joel Embiid is "questionable" for the Philadelphia 76ers' second NBA playoff clash against the Brooklyn Nets as the star continues to deal with knee soreness.

Embiid played in Saturday's surprise 111-102 loss to the Nets in game one of the Eastern Conference first-round series, however he is doubt for Monday's matchup.

The two-time All-Star – who was listed as "doubtful" for the first game of the series – tallied 22 points, along with 15 rebounds in 24 minutes of action.

Embiid missed five of the 76ers' last seven regular-season games. Philadelphia head coach Brett Brown described Embiid's injury as a "slippery slope" when he met with reporters after practice Sunday.

"We are the recipient of Jo trying to inch along slowly and buy time," Brown said. "You win a game, two more days, you win a game, three more days, you might drop one, four more days.

"How do you deliver him responsibly to a later date in ultimately what you hope will be a deep playoff run?"

Embiid averaged 27.5 points and 13.6 rebounds in 33.7 minutes per game in 2018-19. He shot 48.4 per cent from the field and 30 per cent from three-point range.

"It's not as clear cut as you thought it would be on 'how do you maintain a fitness base and still get his knee rest?'" Brown said. "What do we do to help him most now? I believe a solid plan is in place that can deliver him responsibly, incrementally to later dates."

Embiid was involved in controversy during game one as he was seen looking at Amir Johnson's cell phone on the bench. Johnson was fined for the incident.

D'Angelo Russell scored 26 points to lead Brooklyn to the victory. Jimmy Butler poured in a game-high 36 points for the 76ers in the losing effort.