Kevin Garnett will be in the center of attention, no matter who he guards. (AP)

WALTHAM — Kevin Garnett hates being a center. He’s said it since he moved to the position after the All-Star break and he said it again on Thursday night after the Celtics beat the Bucks.

“I hate the five spot,” Garnett said, as if on autopilot. “You put me anywhere on the floor I’m going to play it to the best of my ability. It’s not a preference of mine but it’s something my team needs so I don’t think about it.”

In some ways it’s semantics. Garnett plays the four on occasion when Doc Rivers goes to his bench and he’s guarded both fours and fives since the switch. He’s taking more shots on the offensive end, increasing that number in the second half of the season, but he’s still firing away most from the perimeter with the occasional post-up thrown in for good measure. (Garnett’s passing in the low post remains an underrated strength).

Josh Smith isn’t really a center, either. He played most of his minutes at the four alongside Al Horford and Zaza Pachulia, who are both injured. Like Garnett, he took a more active role in his team’s offense this season, upping his shot attempts by three per game and his usage rate up to 28 percent. Smith is a monster scoring inside and in transition and a streaky, at best, jump shooter, prone to ill-advised long jumpers and 3-pointers.

“He’s going to take the jumper and when he makes it, it’s tough,” Doc Rivers said. “When Josh is shooting the ball [well] throughout the series, it’s going to be a hard series. There’s no doubt about that. He’s going to shoot the ball. We’ve got to respect that shot. What makes him unique is he’s a four or a five that can take you off the dribble.”

There are two ways the Celtics could play Smith. They could use Brandon Bass, a rugged power forward with strength and athleticism. Or they could use Garnett, who is their best defender and a legitimate candidate for Defensive Player of the Year.

Matchups are going to a be a constant storyline in this series. Ordinarily, a team without a true center is a good thing for the Celtics, but they are wary of the Hawks’ big-small lineup, which features over-sized guards like Joe Johnson and Tracy McGrady, wing shooters like Marvin Williams at forward and Smith at center.

“You’ll see [Garnett] on everybody,” Rivers said. “They move Josh to the five and they go with Marvin at the four and Tracy at the three and Joe at the two. That’s a tough lineup. They do it and they do it against us more than any other team for a reason, obviously. It creates matchups and we’re going to have to deal with that.”

The Celtics will try to counter with their regular lineup and force the Hawks into matchups that are favorable to their strengths. According to Rivers, it worked half the time in their two earlier meetings. (For all intents and purposes, the most recent game was a wash tactically due to so many missing players).

Offensively, the Celtics need Garnett to provide some punch. His minutes will still be carefully monitored, but they’re expecting 15-20 shots per night.

“Kevin’s a big key in every series,” Rivers said. “He has to be aggressive. In the series that we’ve won over the years he’s been very aggressive and a go-to scorer. He has to be that for us in this series.”

That doesn’t mean, however, that Garnett will live on the block.

“They’re a great trapping team,” Rivers said. “You’ve got to be careful. If you think you’re just going to post him and win, I think you’d be kidding yourself. If you look at their stats, against post teams they’ve done extremely well. Teams focus on that so much they lose the game. So, we can’t do overdo that. That’s an area that we want to attack through our regular motion. If you get caught trying to do that every time they’ll beat you.”

One of the Celtics’ main concerns is transition defense, and especially 3-pointers on the break. The Hawks had eight players who took more than 100 3-pointers this season and they shot 37 percent, the fifth-best mark in the league. No one defends the 3-point line better than the Celtics and a key will be keeping the floor spaced and getting players back, a tougher task when you’re locked up under the basket.

No matter where he plays and who he guards, Garnett will be key factor and it would be fascinating to watch him return to his roots against a dynamic player like Smith.