New York Knicks forward OG Anunoby, right, tries to pass after recovering a loose ball against Celtics forward Jayson Tatum, center, during the second half of Game 2 of their NBA second-round playoff series on Wednesday in Boston. (AP photo)

When the Boston Celtics left New York last month, they had just finished a season sweep of the Knicks that made it seem as if a postseason meeting would be a simple step on their climb back to the NBA Finals.

Now it’s looking like the one that could trip them up.

In more trouble than they faced at any time last year, the defending NBA champions take a 2-0 deficit into Game 3 this afternoon at Madison Square Garden, where ticket prices are soaring as fans hope to be in the building to see the Knicks try to close in on their first Eastern Conference finals appearance in 25 years.

“We have to go into Saturday’s game and win the game,” Celtics coach Joe Mazzulla said. “That’s just the way it is. We have to win.”

The Golden State Warriors and Minnesota Timberwolves are tied 1-1 in the other series that resumes today in San Francisco, and they have the prime-time spot on ABC’s schedule.

But with Stephen Curry on the sidelines and the Celtics on the ropes, the afternoon appetizer has become the main event.

Boston lost only three games all last postseason. Lose a third straight in this series, and the Celtics would need the biggest comeback in league history to continue their title defense. No NBA team has overcome a 3-0 deficit to win a series.

“The mentality is 0-0. Don’t even focus on that,” Knicks All-Star Jalen Brunson said. “Just focus on the next play, next quarter and don’t look ahead. Don’t look at anything, just try to focus on the task at hand and be present.”

The Celtics should probably be no worse than tied. They had 20-point leads in the second half of both games in Boston, but both ended with Mikal Bridges making a steal to preserve a Knicks victory.

There hasn’t been the same drama in the West series. Minnesota raced to a 13-0 lead and never trailed in its 117-93 victory Thursday, after Golden State led comfortably most of the way in Game 1 even after Curry was lost to a hamstring injury.

Boston Celtics at New York Knicks

When/Where to Watch: Game 3, 3:30 p.m. EDT (ABC)

Series: Knicks lead, 2-0

BetMGM says: Celtics by 5.5

What to Know: The Knicks blew a 2-0 lead in this same round last year, when the Indiana Pacers came back to beat them in seven games. That is the most recent of the 28 times an NBA team has come back from a 2-0 deficit to win a seven-game series.

Minnesota Timberwolves at Golden State Warriors

When/Where to Watch: Game 3, 8:30 p.m. EDT (ABC)

Series: Tied, 1-1.

BetMGM Sportsbook: Timberwolves by 5.5.

What to Know: Draymond Green’s temper is something to watch as the series shifts to San Francisco’s Chase Center for the next two games, given the Golden State forward was hit with his fifth technical foul of these playoffs and is two shy of an automatic suspension. Minnesota missed its initial 16 3-point attempts in Game 1 and finished 5 of 29, but the Wolves bounced back to shoot 50.6% overall and 16 for 37 on 3s in Game 2.

___

AP Sports Writers Dave Campbell in Minneapolis and Janie McCauley in San Francisco contributed to this report.