Miami Heat swingman Justise Winslow has been placed into the NBA's concussion protocol and will be sidelined indefinitely, Heat coach Eric Spoelstra said.
Winslow missed Miami's victory at Phoenix on Thursday with a headache after concussion symptoms began following a blow to his head in Tuesday's loss at Denver.
The Heat, second in the Eastern Conference at 6-2, lost one of their top playmakers ahead of Friday's game at the Los Angeles Lakers, who share the NBA's best record with Boston at 6-1.
Winslow, 23, is averaging 13.8 points, 8.0 rebounds and 4.8 assists in five games for the Heat, who have also been without standout Jimmy Butler for part of the early season campaign.
Winslow, the 10th overall selection of the 2015 NBA Draft, helped Duke University win the 2015 US college championship. He averaged career highs of 12.6 points, 5.4 rebounds and 4.2 assists a game last season.