Marcus Smart was every bit of the spark plug the Boston Celtics had expected him to be during his return to the court this postseason, once again making his presence felt in Game 2 against the Cleveland Cavaliers in a 107-94 win on Tuesday night.

His most notable role was coming in to defend teammate Al Horford after he was shoved in the back mid-air as he tried to finish an alley-oop play. Smart confronted J.R. Smith for the reckless play, which forced officials to separate the two players as they went to replay to assess the nature of the foul.

Head coach Brad Stevens said that at times Smart's impact gets lost in these moments, but not enough to cover up for his impact on the court.

“I think he's as tough as they come, right? He's a true competitor,” Stevens said after the game, according to ESPN's Chris Forsberg. “He matches his intensity with a physical toughness.

“People talk about him all the time. Sometimes they focus on things that don't matter, and the other times they focus on that he impacts winning. We are really glad he's on our team.”

Smart logged 31 minutes off the bench, the most of any player — posting 11 points, five rebounds, nine assists, and single-handedly doubling up the Cavs' steal total with four of his own.

The spark plug has been a key reason the Celtics have had a playmaker at both ends of the floor at all times once the starters are out, giving Stevens and the rest of his teammates a sense of confidence with his gritty play.