Kevin Garnett will be announced in the Timberwolves starting lineup Wednesday night, meaning the Target Center roof might be in danger of cracking from the thunderous reception.

The building will be loud. And emotional. And nostalgic.

And did we mention loud?

Garnett’s homecoming has sent a jolt of excitement through the organization and its fan base. People are understandably giddy after so many years of losing, bad luck and screwy decisions.

The primary talker since Garnett’s trade became official has revolved around the future Hall of Famer’s notorious intensity, his willingness to push teammates, his refusal to let nonsense slide.

Yes, KG remains hyper-competitive.

But largely left unsaid has been Garnett’s potential impact on the court. Not as a mentor, but as a 38-year-old power forward.

Once the euphoria wears off, what kind of player should fans expect to see in No. 21?

“Realistically, I’m competitive,” Garnett said Tuesday at his welcome-back news conference. “I’ve always said that if you can guard in this league, you can play. I’m not a 30-plus-minute guy. I’m not looking for that. I’ve already addressed that with Flip.”

Flip Saunders interrupted Garnett in mid-answer.

“He says that, but he will be the first one complaining about playing time,” Saunders noted.

“My body is different now,” Garnett continued. “I need to listen to my body. I just want to be effective and productive and whatever I can give, I will.”

As wishful as some fans might feel, the Wolves aren’t getting KG circa 2003. Or even Garnett of 2010.

He’s in a different place now. He’s logged 49,764 minutes of NBA basketball. That’s a lot of miles on his tires.

Garnett averaged 6.5 points and 20 minutes per game for Brooklyn last season. He’s averaged 6.8 points and 20 minutes per game this season.

Even an athlete as fiercely competitive and driven as Garnett must come to terms with age and an erosion of stamina.

“I know these are the declining days of my playing days,” Garnett said, “but I think I have so much more to bring.”

Saunders believes Garnett will provide some vintage KG moments in “glimpses.” He can still rebound and defend at a high level. Just not for long stretches.

Garnett and Saunders discussed his role at length before the trade. The Wolves are in the midst of a youth movement and everything about this season revolves around developing the young core.

The organization needs to entrust the youngsters with playing time and responsibility to gauge their future.

Garnett understands the rationale behind bringing him back into the organization. He’s here to teach the young players about the game, about defense, about being a professional, about the importance of preparation.

He’s not here to play 35 minutes a game and carry the team on his shoulders. That was the old KG.

“He would be different in what his expectations were playing-wise if we were in a playoff-type situation,” Saunders said. “I believe he’s coming in with the right type of attitude.”

This in no way suggests the Wolves should put a rocking chair on the bench for Garnett. He’s still prideful in his ability, still determined to produce and play with the same effort and passion in limited minutes.

Garnett reprimanded a teammate in his first practice Tuesday for not running hard enough back on defense. The fire still burns.

“When we’re on the court it’s about working hard,” he said. “I won’t give and settle for mediocre. I don’t think that’s the recipe for success.”

The Wolves expect Garnett’s biggest impact as a player will come on the defensive end, especially on pick and rolls. That’s his strength and one of the Wolves’ weaknesses.

Maybe Garnett has lost a step and can’t play 35 minutes on a regular basis. But his basketball awareness, particularly on defense, will be a valuable asset for a young team.

“He takes such pride in it,” assistant coach Sam Mitchell said.

It will feel a little strange seeing Garnett spend more time on the bench than on the court many nights. He carried this franchise for so many years that his new role will take getting used to.

No one should realistically expect to see the previous version of Garnett.

He’s 38, not 28. As he said, he’s in the “declining days” of his career.

However, his intensity on the court and his love of defense and rebounding haven’t diminished with age. There’s always value in that no matter how many minutes he plays.