The arrival of Jrue Holiday will make the Boston Celtics a serious champion candidate, at least their best shot since 2014, but the upgrade came with a potential risk that can jeopardize the whole season if anything goes wrong.

Here are the details of the trade:

The Celtics sent Malcolm Brogdon, Robert Williams III, an 2024 NBA Draft first-round pick via the Golden State Warriors and the Celtics' own unprotected 2029 first rounder to the Portland Trail Blazers for Jrue Holiday.

It has been no secret since the beginning of this year's NBA offseason that the Celtics tried to trade Brogdon, whose poor health concerned the team. As for Williams III, he belongs to the elite category of players who excel at protecting the rim. But his virtues are not enough for him to earn a consistent spot on the team's rotations, especially in the playoffs, not to mention that he has been haunted by injuries for several seasons.

Holiday is like a combination of Brogdon and Marcus Smart, whom the Celtics sent to the Memphis Grizzlies in the three-team deal that landed Kristaps Porzingis. Even at 33, Holiday is still one of the league's best perimeter defenders and matches Smart in orchestrating. He is also by no means inferior to Brogdon in individual attacks.

Moreover, Holiday won the title with the Milwaukee Bucks in 2021 as the No. 3 player on the team. He knows his role and is willing to play it. The Celtics are the team of Jayson Tatum and Jaylen Brown after he inked that five-year, $304 million contract extension this summer. They need someone to fix their biggest shortcoming without overstepping the authority of Tatum or Brown.

Meanwhile, Holiday doesn't have to shoulder too many offensive duties in the Celtics because Tatum and Brown will take over most of them, especially in scoring. Compared with the team's previous signings to improve the point guard position – Isaiah Thomas, Kyrie Irving and Kemba Walker – Holiday is much more balanced on offense and defense and has never been involved in any locker room trouble.

However, trading for Holiday means the Celtics have made up their mind to lean toward firepower instead of defense in franchise building. They let three of their best defenders, Williams III, Smart and Grant Williams, go during the offseason. Holiday is a great defender, but there is a limit on what he can do as a guard, especially when it's Porzingis and Al Horford standing behind him. Porzingis' 2.24-meter height means he can't close out to guard perimeter players, and Horford, 37, is too old to do that as well.

Though it's not a defensively smart decision to start Porzingis and Horford, the Celtics may have to do that in many games because, first, both big men stretch the floor very well, and second, they don't have the lineup depth luxury anymore to make different styles of squads.

Depth plus health will be two of the most important words for the Celtics. Porzingis has made over 60 appearances in only three seasons since he came to the NBA in 2014. Also, aging can make Horford vulnerable to injuries in the future. The Celtics are likely to count these two, Holiday, Tatum, Brown and Derrick White as their core rotations in the playoffs. It's too short and risky because if anything happens to any of them, the lineup can crumble quickly.