The Boston Celtics had to do something to “shake it up,” said local NBA scout Jeff Nelson.

And trading Marcus Smart for Kristaps Porzingis (and two first round picks) was exactly that.

Nelson, who watched every Celtics game from last season, noted that Porzingis checks a few boxes that even the last two years’ Celtics teams — which  reached an NBA Finals and Eastern Conference Finals — weren’t able to check.

Wizards center Kristaps Porzingis looks to pass against Timberwolves forward Kyle Anderson during a November game in Washington. Jess Rapfogel/Associated Press

“One issue the Celtics have had is when Jayson Tatum or Jaylen Brown go to the bench. They struggle a little bit with scoring,” said Nelson. “With Porzingis there will always be two elite scorers on the floor. In this offense, that’s huge.”

Porzingis averaged 23.2 points per game last season with the Washington Wizards, where he was the No. 1 guy when Bradley Beal was out.

He will be the No. 3 option in Boston.

The other boxes Porzingis checks, according to Nelson?

Al Horford is in a slight decline and Robert Williams’ dependability is again in question. Porzingis gives the Celtics that rim protector and someone who can cover other positions when teams go to pick and roll.

“Porzingis is underrated defensively,” said Nelson. “He’s top five at defending the pick and roll because of his length and athleticism. The Celtics had problems with Horford having to cover Trae Young and Jimmy Butler. Porzingis will be able to handle those types of players, not getting by him, as easily. That’s huge.”

Losing Smart will have to be addressed, at least the point guard part of this game, said Nelson.

He noted while Smart’s desire to take big shots at big moments, maybe wanting a bigger offensive role, probably played a role in facilitating this deal. The time is now for the Celtics to fill the point guard role with a true, backup point guard.

“We’re not talking a superstar,” said Nelson.

“We’re talking somebody, like Denver’s Ish Smith, a backup who can push the pace, move the ball around, create a little. Some version of that. Derrick White is a two-way guard. So is Malcolm Brogdon.”

There are potential issues, similar to what Robert Williams has dealt with, and Brogdon, too.

Injuries.

“The Celtics trainer might be the most important person in the organization, keeping everybody active,” said Nelson. “If the Celtics are healthy, especially with Porzingis, they will be contending for a championship and probably the best team in the East.”