James Harden might not return to the court before the NBA playoffs after suffering a setback in his return from a hamstring injury.
The Brooklyn Nets said the former MVP will remain sidelined indefinitely following an undisclosed issue during an on-court rehab session on Monday.
Harden has played only four minutes since leaving a March 31 game against his former team, the Houston Rockets, with the initial injury.
He sat out the Nets' next two games, then returned for a brief appearance on April 5 against the New York Knicks before missing the last six games.
"We're back to square one... he will be back when he's back," Nets head coach Steve Nash told reporters. "It might be the playoffs. It might be sooner."
The NBA playoffs begin May 22. Brooklyn (38-19) were second in the Eastern Conference entering Tuesday's game against the New Orleans Pelicans.
Harden is averaging 25.2 points, 10.9 assists and 8.0 rebounds in 42 games between Houston and Brooklyn this season.