Now, Walsh is getting his first taste of the NBA playoffs with the Celtics.

“I would say it’s just a lot of learning and taking in information,” said Walsh, a second-round pick in last year’s draft, said before Tuesday night’s Game 1 against the Cavaliers. “Obviously to be here in this situation is amazing. I’m happy that it was Boston. I’m just soaking up as much as I can, learning as much as I can, and just trying to be as positive and uplifting as I can for the guys. That’s pretty much all that I’ve got.”

Walsh said the Celtics have taken a collective approach to mentoring him. He said playing with Maine was a good experience because he could make mistakes and learn from them within the context of a game. Now it’s about listening to veteran players and picking up bits and pieces to add to his game.

“I would say everyone kind of plays a role in that. I talk to [Kristaps Porzingis] a lot about different stuff,” Walsh said. “I talk to Al [Horford], but it’s just a collective effort, a collective family that comes together to try to help the young guy. It’s definitely a role that I feel like everybody has taken on when it comes to giving me advice. [Xavier Tillman] has also been a big help, for sure, so those three guys are probably the biggest help.”

Walsh said the biggest differences between the NCAA Tournament and the NBA playoffs are the physicality and attention to detail.

“It’s a way more physical game here,” he said. “It’s way more attention to detail. In the NCAA Tournament, it’s one game and advance, whereas here you have to beat a team four times. That’s hard, to beat a team four times and advance and not show too much to where another team can get a hint at your secrets and stuff like that. Being meticulous and playing how you want to play each game is important. I’ve picked up on that.”

Walsh said the biggest thing he wants to take away from this playoff run is learning how it feels to win consistently.

“I feel like that’s everybody’s goal now, to win every single game that’s in front of us,” he said. “And that’s what I’m looking forward to, us being able to make history and accomplish something great. That’s the greatest thing anybody can hope for in the playoffs.”

As expected, Porzingis missed Game 1 because of a calf strain.

When asked if Porzingis will be available at any point during this series, coach Joe Mazzulla said, “I have no idea. I just know he is working every day to get back as fast as he can. He’s involved in all the meetings, film, shootaround drills, and then doing what he can treatment-wise. So, I’m not sure.”

Horford is likely to have an increased role with Porzingis out.

“We have to rely on everybody,” Mazzulla said. “We have a bunch of guys that have been here before and we’ve had games during the season without him to be able to establish those identities, but for Al it’s just his toughness and his reliability.

“He’s always available. He’s always there. Both ends of the floor, he has a clear understanding of execution and just brings a level of toughness as you saw in Game 5 [against the Heat]. For us, that’s super important.”

Jrue Holiday finished sixth and Derrick White eighth in NBA Defensive Player of the Year voting, which was announced Tuesday.

Timberwolves center Rudy Gobert won the award with 72 first-place votes, more than three times as many as the runner-up, Spurs rookie Victor Wembanyama.