Although they were missing four players, including two starters, the Boston Celtics turned in what may have been their best defensive performance of the season during a 108-89 victory over the Miami Heat on Monday.Boston coach Joe Mazzulla undoubtedly would like to see a similar effort when the Celtics face the visiting Detroit Pistons on Wednesday night.The Celtics were without Kristaps Porzingis (injury management), Jrue Holiday (left knee), Al Horford (toe sprain) and Sam Hauser (personal reasons), but they held Miami to 35.6 percent shooting from the field (31 of 87).It was the first time this season that the Celtics held an opponent to less than 90 points and also the first time a Boston opponent shot less than 40 percent from the floor.Porzingis and Horford should be back in action on Wednesday, while Holiday and Jayson Tatum (right knee) were listed as questionable.Luke Kornet got the start at center and led the Celtics’ defensive effort by tying his career high with six blocked shots.”When he plays with that level of physicality on both ends of the floor, it makes our team different,” Mazzulla said. “I think his two biggest strengths are his physicality and rim protection when he’s at his best, and then his screening versus different coverages. I thought we saw both of those throughout the game, and he’s just got to continue to do that. But when he plays at a high level, we’re a different team, and we can go to different things.”Boston’s Payton Pritchard strengthened his early-season case for NBA Sixth Man of the Year by making 5 of 12 3-point attempts and scoring 25 points against the Heat. Pritchard has come off the bench to score at least 20 points in each of the team’s past four games.Despite a 3-1 record in NBA Cup group play, the Celtics were eliminated from the event following Tuesday’s results.