Joel Embiid has been set the challenge of winning multiple MVP awards by his former high school coach.

Embiid was named the league's MVP for the first time on Tuesday, edging out competition from Nikola Jokic and Giannis Antetokounmpo.

The Philadelphia 76ers star returned from injury against the Boston Celtics on Wednesday, though could not inspire his team to victory in Game 2 of their playoff series, with the Sixers going down 121-87.

While there is plenty of time remaining for Embiid to take control of that series, Justin Harden – who coached the 29-year-old during his senior year at The Rock School in Florida – says the Philadelphia talisman must continue to improve if he is to be named MVP again.

"Well, in order to get a second MVP he is going to have to be better, right? Because that's just kind of how it goes, you have got to be better than what you were before," Harden told Stats Perform.

"And you know, Nikola Jokic can attest to that. And Giannis can attest to that. And certainly, LeBron [James] can attest to that."

Harden, though, has full faith in 76ers coach Doc Rivers' ability to develop Embiid even further.

He said: "I trust Doc Rivers and what he's done and been able to do.

"But I think he [Embiid] carries a heavy burden as it is. I don't want to add any more to it, but just stay healthy. When you have a bunch of guys flying around at your feet, it's hard to stay healthy, but I hope he does."

As for the legacy Embiid could leave, Harden hopes his former student aims for the stars.

"I think there's no question, he's a top 10 player right now," he said.

"Some would question if he's a top-five player, but if he continues to play as he's been playing, then you start to get mentioned along with the likes of Shaquille O'Neal, Hakeem Olajuwon. 

"They are the guys who won an MVP, who were centres who also led their teams to championships.

"I hope he's able to accomplish that, because every great player gets judged by their team's accomplishments, right? And whether they win a championship or not, that somehow knocks them down.

"I think that he's going to be considered one of the greatest and when you consider his footwork, his touch, his ability to shoot the mid-range and the three-pointers, really, you've only ever seen one guy in Hakeem Olajuwon like him.

"His idol is Hakeem Olajuwon, I'm sure it's just a great feeling to know that you're being compared to your idol. So that's pretty awesome for him."

The Sixers are aiming to win their first NBA title since 1983, but first they must get past the Celtics and advance to their first conference finals series since 2001.

Philadelphia hosts Game 3 of the series, which is tied at 1-1, on Friday.