Ben Simmons remains sidelined after telling the 76ers he’s not mentally ready to play.

But that doesn’t mean the disgruntled point guard has been away for the team’s practice facility.

“He’s been working out,” Doc Rivers said before Thursday’s home game against the Detroit Pistons. “Today he was at shootaround, did a lot of shooting and a lot of stuff with Spencer [Rivers].”

Spencer Rivers is the coach’s son and a skills and development coach for the Sixers. Simmons has been working out at the practice facility for at least the past three days, according to Rivers.

He said Simmons, who has asked to be traded, has been in good spirits. All this comes after Simmons addressed Rivers, Embiid and the rest of his teammates before last Friday’s shootaround. That’s when he told the Sixers that he’s not mentally ready to play.

Rivers doesn’t know when Simmons is coming back to play.

“I don’t think about it a lot,” he said. “I’ve always thought that. I’m assuming yes. But I don’t give that a lot of thought right now.”

Tyrese Maxey is tasked with replacing Ben Simmons. His struggles show it’s easier said than done.

Danny Green has Tyrese Maxey’s back.

Maxey has struggled as the lead guard in the Sixers’ first four games. But Green praised the second-year player.

“He’s doing great, man,” Green said. “He’s got a lot on his plate, throwing things at him every day, every game. He’s handling it like a mature adult for a kid who’s barely 21. He’s understanding and learning each day what you need from him.”

Maxey, who actually doesn’t turn 21 until Nov. 4, definitely has been placed in a tough spot as Simmons’ replacement.

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At this stage of his career, Maxey is more of a slashing, scoring guard. Those strengths don’t mesh well with the starting lineup. He needs to prioritize getting teammates the ball in certain spots and creating spacing.

In addition to being more of a hybrid guard, Maxey shot just 20% on three-pointers through the first four games. So instead of stretching the floor, he’s been left open on some attempts and had opponents go under pick-and-rolls.

And despite Maxey standing just 6-foot-2, the Sixers have also asked him to be in the dunker spot on offense. That’s something the team did often with Simmons, who stands at 6-10, but who now remains sidelined after telling the Sixers he is not mentally ready to play.

“[Maxey]’s probably never been down there in his life, but he’s handling it well,” Green said. “He’s learning; he’s growing; he’s getting us into sets, and he’s figuring it out. It’s a good time to grow quickly as a young fella.”

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Maxey is also being bombarded with instructions from coaches and teammates before having a chance to ask many questions. Through it all, he’s remained humble and has taken criticism well.

“Even though everybody’s throwing eight different things at him,” Green said. “he’s doing a great job with it.”