The 62-17 Boston Celtics, who own the best record in the Eastern Conference by a significant margin, look to be keeping their starting five together for a good long while.

Combo guard Jrue Holiday’s agent, Jason Glushon of Glushon Sports Management, has informed ESPN’s Adrian Wojnarowski that the two-time All-Star, one-time NBA champion and five-time All-Defensive teamer has declined his $37.3 million player option for 2024-25 and agreed to a massive new four-year, $135 million contract extension to stick around with the Celtics through the 2027-28 season.

The 15-year pro is averaging 12.5 points on a hyper-efficient slash line of .481/.431/.833 (he’s evolved into a lethal corner three point shooter late into his career), 5.4 rebounds, 4.9 assists, 0.9 steals and 0.8 steals a night, across the 68 healthy games he’s played thus far. His scoring and passing are considerably down from his 2022-23 numbers while with the Milwaukee Bucks (19.3 points on .479/.384/.859 shooting splits, plus 7.4 assists), but that’s due in part to the fact that he’s playing on a much deeper team, with more talented passers, playmakers and scorers alongside him than he had on a thinner Milwaukee club that fell in the first round of last season’s playoffs.

Holiday, 33, is just the fifth option on offense for the Celtics. All-Stars Jayson Tatum and Jaylen Brown lead the way with averages of 27 and 23.1 points a game, respectively. Another newly-obtained trade addition, injury-prone center Kristaps Porzingis, is averaging 20.2 points himself. Holiday’s backcourt mate Derrick White, another defense-first guard, is also essentially the team’s point man, averaging more points (15.3 on .463/.398/.901 shooting splits) and assists (5.2) than the newly-extended vet.

Wojnarowski notes that Holiday’s hefty new contract will put Boston far above the league’s anticipated salary cap in 2024-25 (barring trades), which will significantly impede the kinds of pieces that team president Brad Stevens can add to his team’s roster next year. That said, Wojnarowski adds that the new deal will actually help Boston save money on its overall cap next year, given that it pays him a bit less annually ($33.5 million) than his prior, now-declined player option.

Signing the 6-foot-4 UCLA product through his age-37 season is a risky proposition, especially for a guard whose play is predicated on defense. Yes, Holiday doesn’t seem to have exhibited many signs of age-related decline at this stage, but how will he look in two years? Three?

The Celtics no doubt are hopeful that the team isn’t just paying for past experience, but future production, too. Short-term, the deal makes plenty of sense, as it keeps a core five together that has helped lead the team to the top overall record in the NBA, the league’s best offensive rating (124.7) and its third-best defensive rating (113).

Holiday arrived in Boston as the centerpiece of a trade with the Portland Trail Blazers, who acquired him in their deal with the Bucks to land All-Star point guard Damian Lillard late in the 2023 offseason.