BOSTON – There isn’t a whole lot of competition for the Celtics this preseason, which isn’t a surprise for a team that returns 13 players from a championship team. Kristaps Porzingis’ absence for the first two months of the year opens the door for a placeholder on the bench, especially following the departure of Oshae Brissett via free agency.

Jordan Walsh is the youngest player on the Celtics roster at 20 years old, but after the first two weeks of training camp he is determined to take advantage of this opportunity. Walsh had great success with the second unit in his first two preseason games and earned some praise from Joe Mazzulla for his performance on Thursday.

“Just defensive, versatile and guarding all five positions,” Mazzulla said. “On offense, you have to be able to be versatile, know what the matchup is, know what the coverage looks like and know what the right solution is in coverage. And I thought he did a really good job on both ends of the floor.”

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Walsh is coming off a solid rookie season, most of which was spent with the Maine Celtics, but he had a brutal week with Boston in Summer League in July, particularly with his 3-point shooting. Walsh admitted he had to change his attitude after the disappointing performances and Mazzulla is happy with how he has made that change three months later.

“He approached him with a lot of trust,” Mazzulla said. “I think it’s hard for young people to trust that you’ll be rewarded for the simplest things, and it’s hard to trust that when you’re young.” And I understand the perspective he had, but he’s consciously changed his perspective and just trusts that the most important things are the simple things, and that’s how you’re measured and that’s how you grow. And I think he really showed that in the first two games.”

Walsh will compete against more experienced players, including off the bench Jaden Springer, for opportunities that could arise on nights Porzingis and Al Horford are out. Rookie first-round pick Baylor Scheierman could also be a factor once he learns Boston’s system. At the moment it looks like Walsh could have an early lead over the competition.

“It’s an acknowledgment that the simple things are rewarded,” Mazzulla said. “And I think the way you have to hold these people accountable is just giving them a clear understanding of, ‘These are the things you’re going to be judged on, not the external things that you are.’ can’t control.’ or what you may think is important. And here’s what really matters: If you do that, you’ll get better and you’ll be able to help our team. And he’s done a good job of adapting to them.”