Joakim Noah can still be an asset on the Knicks — just more so off the court as a tutor/mentor and definitely not as their starting center.

That scenario is a no-brainer now, whenever Noah returns to action. Noah has a severely sprained ankle that will require an MRI exam on Thursday.

Whether it’s serious or not, Noah’s starting days are over. The Bulls discovered that last season when they had him come off the bench for all but two of his 29 games before season-ending left shoulder surgery last January.

Because of age and injuries, Noah has lost the lateral quickness that once made him a terrific defender, TNT’s Brent Barry told The Post last week.

On Wednesday, with Kristaps Porzingis and Noah out, the Knicks pummeled the Celtics on the boards, 57-33, and the scoreboard, 117-106, in their extremely rare victory over a solid ballclub.

The Knicks are now — incredibly — 5-0 when Noah misses games. The Knicks are 14-24 when he plays. You don’t need Archimedes to calculate the $72 million elephant in the room.

When Porzingis gets back — likely for Saturday’s game against the Suns — the new starting alignment will have to be Porzingis at center, Carmelo Anthony at power forward and the active, cheerful, all-over-the-court Lithuanian rookie Mindaugas Kuzminskas at small forward.

Knicks coach Jeff Hornacek hinted on Monday that Porzingis may play center upon his return.

The common thinking when Noah inevitably got benched was Kyle O’Quinn would slide into the starting lineup.

But the Porzingis-Melo-Kuzminskas alignment is better and will make the Knicks younger, more energetic, more athletic and perhaps make up for Anthony’s legs not being what they used to be.

That said, Noah may be a useful piece off the bench on some nights in limited doses — no more than 10 minutes per night. And it’s OK to give Noah a DNP-coach’s decision on occasion. De-emphasizing Noah will give room for the Spanish rookie center Willy Hernangomez to get some nightly action. There may even be a few minutes for Marshall Plumlee in games when the Knicks lack spit and vinegar.

In the past, when the Knicks replaced Porzingis or Anthony, Lance Thomas soared into the starting lineup. But Thomas doesn’t do nearly the things Kuzminskas can do — and draining 3-pointers is just one feature. Plus Thomas is out another week with his fractured orbital bone that will require adjusting to a face mask.

In his second straight start, Kuzminskas scored 17 points in Boston on tip-ins, 3-pointers and drives. Kuzminskas moves well without the ball and has nice chemistry with Porzingis — and Anthony genuinely seems to like him.

Kuzminskas grabbed six rebounds, including three on the offensive glass. He’s getting better defensively as he learns the league and sees teams a second time. He told The Post the rookie wall won’t hit him. Kuzminskas played roughly 65 games last season between the Spanish League, Euro competitions and the Olympics. He’s also 27 years old.

Hornacek has been excruciatingly slow in taking to Kuzminskas because of a curious loyalty to Thomas, but this is the frontcourt that can save this almost-lost season, and save Anthony, too.

By now, even Knicks president Phil Jackson has to realize he goofed on the length (four years) and dollars ($72 million) of Noah’s contract.

The Post has learned the stretch provision (spreading out the cap hit over a longer stretch of years for a waived player) still will be in the new CBA. Jackson can use it on the Hell’s Kitchen product this offseason or next.

Noah remains a leader and a terrific teacher. On Wednesday, he was in the ear of Hernangomez, who wrecked the Celtics for 17 points and 11 rebounds. He is also a sage for Porzingis, Plumlee and O’Quinn.

The time for political correctness in handling the rotation is over. Hornacek appears aware.