Could Sam Hauser be the difference-making shooter the Celtics have been missing?

Sam Hauser has nailed nine 3-pointers during the Celtics' two preseason games.Charles Krupa/Associated Press

Since the days of Eddie House, the Celtics have been searching for a floor spacer, a premium 3-point shooter who could relieve the pressure on the primary scorers. The quest has been fruitless the past several years.

The Celtics like to shoot 3-pointers but are average at making them. Jayson Tatum and Jaylen Brown are solid 3-point shooters. Marcus Smart and Al Horford are streaky. Derrick White has struggled in his career. Payton Pritchard floundered during the NBA Finals.

Sam Hauser perhaps wasn’t ready for a more prominent role last season. But he has been given an opportunity in the wake of Danilo Gallinari’s injury (he tore an ACL during the summer and will be out indefinitely). And through two exhibition games, Hauser is proving to be that difference-making shooter the Celtics lacked last year.

The stakes will be considerably higher when the regular season begins, but Hauser’s nine preseason 3-pointers — including five in Wednesday’s 125-119 overtime loss to the Raptors — are an indication that he’s ready for that role.

The first two Celtics units appear to be ready for the season. The ball movement is crisp. There is no selfish play. Brown is playing with a furor and enjoyment at the same time.

The biggest concern is filling Gallinari’s role. The Celtics need another shooter to open up the floor, especially with Brown and Tatum out there. Hauser is showing early that if he gets an open look, there’s a strong possibility it’s going down. That’s what the Celtics have needed for years.

Shooters are a commodity in the NBA. The Celtics believed they had their 3-point specialist when they drafted Aaron Nesmith 14th overall in 2020, but in two seasons he was nothing more than a hustling defender with an erratic shot. He was traded to the Pacers in the Malcolm Brogdon deal.

The Celtics signed undrafted Max Strus out of DePaul in 2019, but he was beaten out by Javonte Green for the final roster spot, and then-president of basketball operations Danny Ainge decided to keep Tremont Waters and Tacko Fall on two-way contracts.

Strus eventually landed in Miami, where he was a 41 percent 3-point shooter in 68 games last season and a postseason starter. That encouraged the Celtics to wait on Hauser to develop instead of making a short-term roster move.

Hauser argues a fourth-quarter call -- with help from the fans -- in Wednesday's preseason win at TD Garden.John Tlumacki/Globe Staff

Hauser wasn’t quite ready last season — or he didn’t gain Ime Udoka’s trust — but he has worked feverishly to become more consistent beyond his shooting. He should be part of the second unit this season, at times spending time on the floor with Brown and Tatum.

“He’s worked really hard and does a great job playing off of others and kind of taking what the defense gives him,” Celtics coach Joe Mazzulla said. “He really has a good feel for the game and he does a great job of fitting in with the lineups when he’s in there.”

Depth was a major issue for the Celtics last season, and it was the primary reason — besides the brilliance of Stephen Curry — that they lost the NBA Finals. They added Brogdon, and the hope is that Grant Williams, White, and Pritchard take steps forward while Hauser works himself into the rotation.

“My job is to just space the floor, find openings, and be an outlet for those guys like [Tatum and Brown],” Hauser said. “It’s not easy to come in cold and try to make shots. But that’s what I’m asked to do. That’s kind of what I’m known for is shooting, and that’s how I can help this team in the best way possible.”

Hauser’s key is to hit enough 3-pointers to force defenders away from the paint. Having multiple perimeter shooters makes an offense flow, and that’s what every NBA team is seeking. Opposing defenses, especially the Warriors, did not respect the Celtics’ 3-point shooting outside of Tatum and Brown. They locked up the paint, preventing the scoring duo from driving without multiple defenders.

Gallinari, at 6 feet 11 inches, would have been a nightmare matchup because of his size and ability to shoot. What’s more, he has such a reputation as a premium shooter that defenders would have guarded him away from the paint. Hauser will have to earn that type of respect, but the hope is that scouts who watched the first two preseason games will note that he requires defensive attention.

Could Hauser become a key piece of the Celtics' offense?Mary Schwalm/Associated Press

“Sam can shoot, I tell him that all the time,” Tatum said.

Tatum and Hauser have a long-running friendly debate over who’s the better shooter. When asked if Hauser is better, Tatum responded, “Hell no. I tell him all the time, if I was that wide open and all I had to do is catch and shoot, I would make a lot more shots as well. I tell Sam to send me a thank you card.

“Sam is obviously a great shooter and his game has come a long way. I’m happy for him. I’m glad he’s getting the opportunity and he’s obviously making the most out of it. We’re going to need him. He’s going to have to play well for this team this year.”

The hope is Hauser is ready for the big stage, because the Celtics definitely need more consistency from beyond the arc. They have been searching for that elite shooter for a decade. Hauser may be the best candidate yet.