Evan Fournier, left, could join the Celtics as soon as Saturday after his trade from the Orlando Magic. Phelan M. Ebenhack/Associated Press

BOSTON — Celtics President Danny Ainge didn’t get everything he wanted at the trade deadline. He hopes it was at least the start of changing the tone inside his team’s locker room entering a pivotal stretch of the season.

“I want our players to feel hope. I want our coach to feel hope. I sense some discouragement internally with our guys,” Ainge said Friday. “And so, that was one reason we did something now as opposed to waiting somewhere down the road.”

What he did was send reserve point guard Jeff Teague and two future second-round draft picks to Orlando in exchange for 28-year-old Evan Fournier, a wing scorer and playmaker Ainge believes can take at least some pressure off Boston’s core of Jayson Tatum, Jaylen Brown and Kemba Walker, and re-energize his team over the latter part of its schedule.

Boston entered Friday with a 21-23 record, having lost six of eight since returning from the All-Star break. The Celtics were eighth in the Eastern Conference and in danger of missing the playoffs for just the second time in Brad Stevens’ eight seasons as coach.

In Fournier, the Celtics add a player averaging career highs in scoring (19.7 points per game) and assists (3.7 per game). Boston was in the mix to add both Fournier and his former Magic teammate, All-Star center Nikola Vucevic. Instead, Vucevic was dealt to Chicago.

Boston made a three-team trade with the Wizards and Bulls that brought center Moe Wagner and reserve Luke Kornet to the Celtics. That move cost them big man Daniel Theis and guard Javonte Green in a salary dump to help avoid being over the luxury tax threshold.

The Celtics may still not be done, with Ainge expressing openness to the possibility of exploring the buyout market.

What’s been most surprising to Ainge is how poorly his team has performed on the defensive end.

Strong play on defense has been a staple of the Celtics’ deepest runs since Stevens took over in 2013. But the intensity has fallen off considerably. Boston has a defensive rating that ranks 24th in the NBA, down from fourth last season. Its scoring is also down, from fifth in 2019-20 to 17th this season.

“Consistency. I feel like since the beginning of the season, it’s been a challenge for us. For whatever reason,” Ainge said. “I’ve seen so many good things in so many games this year. And yet there are moments and quarters that have just been a disaster.”

While Fournier wasn’t expected to be available to play until at least Saturday when Boston visits Oklahoma City, one change that could come sooner is more playing time for center Robert Williams.

In his third season, Williams has been the best option on the defensive end among Boston’s big men. He’s up to 1.7 blocks per game and his rebounding is at a career-high 6.4 per game. He’s also been more aggressive offensively, running the floor and beating opponents to the rim.

Ainge said Williams has also improved defending the pick-and-roll.

“He still has a long way to go. We think he still has even a bigger upside ahead of him,” Ainge said. “But, yeah, it’s going to be a bigger role for Rob at this moment.”

Though Ainge said some efforts to make improvements “didn’t work out” at the trade deadline, he doesn’t view Fournier as just a rental for the rest of the season. Fournier is in the final year of a five-year, $85 million deal and becomes a free agent this summer.

“I feel like we’re trying to get better all the time. Every trade deadline. Every offseason. And I felt like there was an opportunity,” Ainge said.

What his team does now will go a long way in determining whether bigger and more drastic changes could be on the horizon in the offseason.