Simmons has played his best basketball of the season since recovering from left knee soreness and rejoining the starting five but struggled against Orlando on Tuesday (AEDT) and left the court in the second quarter.

Scans revealed a left-calf strain that will rule the former No.1 draft pick out of Thursday's game against the Washington Wizards, and follow-up meetings with Toronto and Boston.

"He's out for the next three games," Nets coach Jacque Vaughn said before the game against the Wizards.

"That's what we are, and then we'll get to a point where we'll take a look at him after that.

"It ended up being an upper-calf strain. We'll see where he's at after these three games that he'll miss."

Either Joe Harris or Edmond Sumner appear likeliest to replace Simmons in the starting five for the game against Washington at Barclays Center.

After the win over the Magic, Vaughn said "the accumulation of games" had affected Simmons, who missed last season through a back injury and mental health leave.

"His cumulative load begins to add up. It's really stretching him sometimes," Vaughn said.

Brooklyn's Japanese international Yuta Watanabe will miss a sixth-straight game with a hamstring complaint.

Australian Associated Press