Last year, the Celtics had to win to face the Nets. This time, it’s the other way around.

Jayson Tatum (right) and the Celtics could get another shot at Kyrie Irving and the Nets.Steven Senne/Associated Press

Last year, the Celtics were in a precarious position, needing to win their play-in opener to face the Brooklyn Nets in the first round of the playoffs.

The Celtics were shorthanded with Jaylen Brown out sidelined with a wrist injury, and they were carried by Jayson Tatum, who scored 50 points in the 118-100 win over the Washington Wizards.

The win did little to generate momentum against the Nets. The Celtics lost the series in five games. Kemba Walker got hurt in Game 3 and the Nets had little trouble with their rivals to the north and Kyrie Irving drew the ire of Celtics fans by stepping on the leprechaun logo at center court.

This time, it’s the Nets who have earn the right to face the Celtics, taking on the Cleveland Cavaliers on Tuesday at the Barclays Center in the first play-in game. The winner faces the Celtics starting Sunday at TD Garden.

Brooklyn was primed for an NBA Finals run in October, with a healthy Irving, James Harden, and Kevin Durant. The enthusiasm quickly cooled when Irving decided not to get vaccinated and couldn’t play home games because of a New York City ordinance.

That issue hovered over the team all season, and Harden, unhappy because he was forced to shoulder more of the burden in Irving’s absence, asked for a trade. Nets general manager Sean Marks obliged, swapping Harden for Philadelphia’s Ben Simmons, Seth Curry, and Andre Drummond.

Simmons, a three-time All-Star, hasn’t played a minute for the Nets but could return during the playoffs. Drummond and Curry have played more prominent roles, but the Nets have essentially turned into a two-man team with Durant and Irving.

Kyrie Irving and Kevin Durant are set to lead the Nets into the playoffs.Seth Wenig/Associated Press

The results this season were 10th in the NBA in offensive rating and 20th in defensive rating. The Nets allowed 115.6 points per game after the All-Star break compared with 107.3 for the Celtics.

Brooklyn is heavily favored to beat the Cavaliers, who got off to an impressive 35-21 start with a nucleus of All-Star point guard Darius Garland, center Jarrett Allen, Rookie of the Year candidate Evan Mobley, and a resuscitated Kevin Love. But injuries and inconsistency marred their second half, and they finished 9-17 and fell to the eighth seed.

Still, Cleveland should provide a challenge for Irving and Durant. The franchise has been seeking relevance since LeBron James bolted for Los Angeles and this is a prime opportunity.

“This is a special time of the year, going against a team such as the Cavaliers is something to look forward to,” Irving said after the Nets fought off the Indiana Pacers in the season finale. “They’re going to make adjustments and we’re going to make adjustments and it’s going to be an all-out battle.”

As has been Irving’s history, he had no issue acknowledging his star power and how that offered more appeal for this play-in game.

“No. 1, having somebody in the back room hip-hip hooraying whoever created the play-in tournament because last year you got Steph [Curry] and LeBron and this year you got me and KD against the Cavs,” Irving said. “It feels like of those must-wins and you know the ball’s going to be tipped and it’s not going to depend on anything other than will, skill, physicality, how well you know the other team’s offensive schemes. Prepare for anything that can happen.”

The Nets would be a formidable opponent for the Celtics, primarily because Durant and Irving are capable of 50-point eruptions. Seth Curry is a sharpshooter that can’t be left alone, Boston native Bruce Brown is a pesky defender, and Drummond gobbles up rebounds.

If the Nets beat the Cavs, how will Kyrie Irving handle another playoff series against the Celtics.Matthew J Lee/Globe staff

Irving said the pressure of having to qualify for the play-in has galvanized the team, which was unnerved by the Harden trade, Durant’s knee injury, and Irving’s own vaccine issues.

“Every game was pretty much a must-win and it gave us a great test, a great challenge, and I’m glad we passed a few of them,” he said. “There’s still some ups and downs within the flow of the 48 minutes we have to fix ... We could come up with every excuse in the world of what happened this season. So many things transpired, ups and downs and now we’re finally here and we’re able to perform with one another for the first time in an intense environment like the playoffs. It’s a great challenge and I’m looking forward to it and I know my guys are too.”

The pressure is all on the Nets to win. If they lose, they would host the winner of Atlanta-Charlotte on Thursday for the right to be the eighth seed. If they win, it’s a likely grueling series with the Celtics, who haven’t forgotten last year’s drubbing.

“[The past few weeks] forced us to grow closer very quickly and really focus on what’s going on in the locker room and what we want to accomplish,” Nets coach Steve Nash said. ”Same scenario for both teams, whoever plays better is going to win.”