Steve Nash could not confirm that Ben Simmons will return to the court for the Nets game against the Celtics on Monday.
Nash said after Sunday's practice that he had no idea.
Simmons initially called Game 4 a reasonable target for his return from a back injury, but according to Adrian Wojnarowski, he plans to play.
On Sunday, Nash said it was up to the player to make the call.
The coach said that part of the decision had to be Ben.
Simmons has yet to play for the Nets this season.
The three-time All-Star sat out the beginning of the year for mental health reasons. He was unable to play for his new team because of a back injury.
Nash hasn't always been kept in the loop about Simmons' rehabilitation.
Celtics on NBC Sports Boston @NBCSCelticsSteve Nash on Ben Simmons potentially returning for Game 4: "That's news to me." pic.twitter.com/eUhvWWXqt6
Simmons is almost out of time with the Nets on the verge of elimination.
Simmons averaged 15.9 points, 8.1 rebound and 7.7 assists per game in his career, and he was an impact player in his previous stop. He has been named first-team All-Defensive in each of the past two years.
The Nets have allowed 110.7 points per game so far in the series. The forward has been unstoppable with 29.7 points per game, including 39 in the Game 3 victory.
Adding Simmons to the rotation would give Tatum a different look to contend with, but his health status remains a mystery.