The champion Celtics should still be title favorites next season

All of the key players from this Celtics run are under contract for next season. Jaylen Brown is entering the first year of a five-year supermax extension, while Jayson Tatum is likely to sign a five-year supermax extension this summer for roughly $315M. 

Al Horford, Derrick White and Sam Hauser are signed through next season, Kristaps Porzingis is signed through 2025-26 and Payton Pritchard is locked up for four more seasons.

The NBA's new CBA rules punish high-payroll teams who exceed the salary threshold by too much, limiting their ability to execute sign-and-trade deals, use certain cap exceptions or take back more money than they send out in trades. 

But the Celtics, with two stars in their primes, likely only need to add around the margins with minimum-salary players.

After trading for Porzingis and Jrue Holiday (signed through 2027-28), Boston still has its own first-round pick for the next three years. That gives them flexibility to attack a pick in trades, and a chance to add a low-priced player going forward. 

And considering the NBA's new TV deal could be worth $7B per year, the Celtics can reasonably expect the league's salary cap to rise 10% each season.

However, the team may get quite expensive after next year. They'll be paying Tatum and Brown over $100M combined, while All-Defensive guard White is a free agent. 

Boston will also have to replace Horford, who is still productive at age 38, but it might be hard to rely on him in what would be his 19th NBA season.

But they can figure all that out 12 months for now. Monday night, the Celtics will enjoy champagne-filled celebrations, knowing most of the new champions will reunite ready to repeat in the fall.