BOSTON — After he fouled out early in the fourth quarter Wednesday night, after he said his piece to referee Tony Brothers, Jalen Brunson took a seat on the bench and, with the arena cameras focused on him, sending his image to the Jumbotron at center court, he waved.

There was no angry gesture, just the simple wave. And maybe that should have brought a chill to the crowd at TD Garden and served as a message of hope for Knicks fans at Madison Square Garden entering Game 6 Friday night.

Brunson is not one for fiery speeches or wild gestures, but in the moment it seemed as if there was an assurance that he would be ready when the Knicks host the Celtics with a three games to two lead and another chance to close out the Eastern Conference semifinal series.

Now, why there is a need for a Game 6 . . . that’s another story. The Knicks had a chance to close out the Celtics Wednesday and instead left the arena grumbling about mistakes, communication, some officiating, and promising to be better next time. But from Brunson there were no complaints, no excuses. So take the wave as a sign.

There is a history for this. Since joining the Knicks, Brunson is averaging 32.5 points and 7.4 assists following a loss in the postseason — and the Knicks have won nine of those 12 games (one of the losses was Game 7 against Indiana last year, when he suffered a broken hand).

In Game 6 of the opening round against Detroit, Brunson not only came out with a 7-for-9, 15-point first quarter, but capped it with a game-winning three-pointer — which finally elicited a response to the Detroit crowd that had been taunting him all series long, a simple kiss blown to the crowd.

It was of little surprise that Celtics played with desperation Wednesday, back home after seeing Jayson Tatum lost to a ruptured Achilles tendon in the closing minutes of Game 4, and facing elimination.

The Knicks should have been familiar with this attitude, having listened to their own coach Tom Thibodeau preach it regularly, answering, “Next man up. We have more than enough to win,” as key players would fall to injury.

“Yes, they are missing a big piece,” Brunson said. “But like I said before, they are a team, a well-oiled machine that has been in situations where they have played without him. They’ve played well and we need to understand that, and trust the game plan and play to win. It’s that simple.”

Simple seemed like a reach, but if the Knicks knew what was at stake Wednesday, there is no need to remind anyone this time. The Knicks entered Game 5 with three chances to knock out the defending champions, and the next one (or two) will bring a little more pressure. But at Madison Square Garden, with a chance to not only to reach the Eastern Conference Finals for the first time in 25 years, but close out a playoff series at home for the first time in just as long, it may seem like just the right confluence of circumstances to find a bit of magic.

But the Knicks aren’t looking for magic tricks.

“That is such a stupid question,” the normally amiable Josh Hart said when asked about the importance of winning Game 6. “Every game you want to win, bro. There’s no added anything. Like, every game you want to go out there and win. It doesn’t matter whether it’s at home or away. That question is stupidity to me. Every game you go out there, you want to win, you go out there and compete. Obviously, we didn’t do that. Next game is our next game and that’s all we’re focusing on.”

“I’d like to win a closeout game anywhere, it doesn’t matter if it’s home or away,” Karl-Anthony Towns said. “I love our fans, but I know our fans would appreciate if it was done on the road as much as if it was done at home. It’s about winning every single game possible, putting ourselves in position to win, and I think that what’s more disappointing is [Wednesday] we didn’t put ourselves in position to win.”