LOS ANGELES (AFP) — The National Basketball Association (NBA) champion Boston Celtics launch their bid for a title repeat in a playoff landscape altered by the emergence of the Cleveland Cavaliers and Oklahoma City Thunder, and the intriguing threat of the new-look Los Angeles Lakers.

The Celtics, virtually unchanged from the team that lifted the franchise’s record 18th title last season, completed the best regular-season by a defending champions since the 2015-16 Golden State Warriors, finishing second in the East with a 61-21 record — third best in the league.

They led the NBA in three-pointers with nearly 18 per game and rolled into the playoffs winning 25 of their last 30 games.

But the Celtics say they’ll be working from a clean slate when they open their post-season campaign against the Orlando Magic on Sunday.

“I’ve said it a lot: We’re not defending the championship,” star forward Jayson Tatum said. “We won last year. Can’t nobody take it from us. But last year is last season. That’s out the window. We’re not worried about anything beside the Magic right now.”

The Celtics are optimistic that last year’s NBA Finals Most Valuable Player Jaylen Brown will be ready to go against Orlando after receiving injections to treat a knee injury that sidelined him for the last three games of the regular season.

“He actually looks good,” said teammate Kristaps Porzingis, who echoed Tatum’s view that the Celtics are starting from scratch as they try to become the first team since Golden State in 2017-18 to win back-to-back titles.

The regular season was dominated by the Cleveland Cavaliers and Oklahoma City Thunder.

The Thunder, already first in the Western Conference last year, compiled the best record in the league, amassing 68 victories compared to their 57 last season behind Most Valuable Player candidate Shai Gilgeous-Alexander.

Coach Mark Daigneault’s Thunder are the youngest team in NBA history to secure a number one seed.

Gilgeous-Alexander owns a league-best average of 32.7 points per game, OKC ranks fourth in total offense and third in defense and Gilgeous-Alexander believes they can respond to any opponent.

“We have a ‘whatever it takes’ mentality,” Gilgeous-Alexander said. “The goal is to win. However you get it done, it’s a step in the right direction.”