MILWAUKEE — Since clinching the NBA’s No. 1 overall seed last Wednesday, the Celtics have understandably taken a more cautious approach to the last stretch of the regular season. They have not played at full strength in their last three games, giving their regulars some appropriate rest with nothing meaningful left to play for and a long playoff run ahead.

With three regular-season games left – including a home back-to-back on Thursday and Friday – that approach will probably continue. But it may be worth considering using one of these games as a final test run, something of a tune-up before the postseason. With Game 1 of the first round set to begin on April 20 or 21, that would mark more than two weeks since the Celtics last played at full strength. There could be a benefit to have one game where the Celtics simulate a playoff rotation to stay sharp.

“I don’t know, I don’t really put too much thought into it,” Celtics coach Joe Mazzulla said. “If we get one before the end of the season, we do it. If not, you’re not. We’re in a unique position. There’s no real right or wrong answer. You got to kind of check a bunch of boxes between health, rhythm, getting better. So if it presents itself, it’ll be good. But at the end of the day, like, there’s a bunch of different ways to get better around this time and there’s no right or wrong because of the uniqueness of it.

“So, sometimes it’s been film, sometimes it’s been walkthroughs, sometimes it’s been playing, sometimes it’s been a little bit of everything.”

The Celtics are certainly in a unique position. Health should be the priority, but with that comes a sacrifice of rhythm. In wins over the Kings and Blazers, the Celtics rested their starters for the entirety of the fourth quarter. In Tuesday’s loss to the Bucks, they experimented with some different lineups and were beaten convincingly by a more motivated opponent. The C’s responded from a poor shooting first half with a strong comeback bid in the third quarter, but there wasn’t enough reason to empty the gas.

The Celtics have been consistent in their mindset and play all season, but without anything significant to play for over the final week, it can be easy for human nature and some complacency to take over. They don’t seem worried about it, but when the playoffs come it might be easier said than done to suddenly dial it up for the most important games.

“I don’t know if there’s really a snap of your fingers and you’re there,” Derrick White said. “I think we’ve just been focused on it the whole year and we’ve had the right mindset all year, so I don’t see why we’d change now.”

Following Sunday’s regular-season finale against the Wizards, the Celtics will have a week off as they wait to find out their first-round opponent via the play-in games. While they might not be going full throttle to finish the regular season, Jrue Holiday is certainly expecting Mazzulla to keep them engaged during the week off.

“I’m pretty sure during the time Joe’s going to have us do some crazy ass drills to get us all ready,” Holiday said.

Tatum at the 5?

With Kristaps Porzingis and Al Horford both out of Tuesday’s loss to the Bucks, the Celtics experimented with some lineups that included Jayson Tatum playing center. It included one stretch when he was matched up with the 7-foot-1 Brook Lopez.

“I ain’t enjoyed that,” Tatum said. “Fighting with Brook Lopez. So you know, hopefully I ain’t gotta do that no more.”

Mazzulla said it wasn’t specifically planned, but the game and the personnel presented the opportunity. On a night when the Celtics struggled on offense, they found some easier mismatches with five perimeter players on the floor.

“If I’m the tallest guy out there, we got five guys who really can take you off the dribble, push the tempo, shoot, create for others,” Tatum said. “So guarding us is going to be tough. And obviously, we can switch everything. We just gotta gang rebound, obviously, when we’re that ‘small’ out there. But it was something that faster lineup we can go to.”

The absences of Porzingis and Horford also allowed Xavier Tillman to get the start, which gave the Celtics another look they can put on film. The Bucks trailed off defending Tillman at the 3-point line, and he hit a couple of open triples.

“He’s not the shooter that KP is, but X can knock down shots,” Tatum said. “He had some open ones, he hit a few and some other ones, he didn’t. But that’s part of it. You gotta generate good looks and find the open man. At the end of the day, it’s a make or miss league. Hopefully, we don’t have any games in the playoffs where we don’t have Al and KP and have everybody healthy.”

Tip-ins

Giannis Antetekounmpo seems to have avoided serious injury after suffering a left calf strain against the Celtics on Tuesday. According to multiple reports, the Bucks star’s MRI revealed no damage to his left Achilles tendon. His return will be based on treatment and rehab response. …

The Maine Celtics, who won Game 1 of the G-League Finals on Tuesday, can win the championship in Thursday night’s Game 2 at the Oklahoma City Blue. …

The Celtics have a loaded injury report for Thursday’s game against the Knicks. Jaylen Brown (left hand sprain), Tatum (right knee contusion), Porzingis (right hamstring injury management), Holiday (left patella tendinopathy), Horford (left big toe sprain) and Tillman (right knee tendon irritation) are all questionable.