The Knicks will never have to think of what could have been.

Before the Knicks altered the direction of their franchise by taking Kristaps Porzingis with the fourth-overall pick in the 2015 draft, the team was also considering drafting center Willie Cauley-Stein, who was widely considered the best defensive player available, and worked out for the Knicks.

While Porzingis has since become one of the league’s best players — lighting up Madison Square Garden on Saturday night with another offensive masterpiece — Cauley-Stein, who was drafted by Sacramento with the sixth pick that year, has yet to fill the immense potential he displayed while taking Kentucky to the Final Four.

Cauley-Stein was largely invisible in the 118-91 loss to the Knicks, struggling with foul trouble, and finishing with five points, three rebounds and three assists.

“I thought I had a pretty good chance of coming here, but they ended up picking the right guy,” Cauley-Stein told The Post following the loss.

Cauley-Stein was like every other player against Porzingis, having virtually no chance of slowing the most offensively versatile 7-footer in the league.

But while guarding Porzingis, Cauley-Stein believes he saw what he is capable of, even if the league has rarely seen a talent as unique as the Knicks’ franchise player.

“I think I just gotta get more selfish,” said Cauley-Stein, who hit 2-of-6 shots, and is averaging 8.9 points this season. “Offensively, I gotta get to the point that I’m just going at dudes like him. Guarding him, and then watching his game, you take away, oh, this is what he’s doing. I have the same body size, the same skill-level, just transfer it over to a game now. But being behind in the race, he’s been doing it for a while.”

Cauley-Stein, 24, said he believes Porzingis is in the perfect situation, with Carmelo Anthony’s absence giving him the opportunity to become a superstar, and the Kings center admits he wonders what would have happened if the draft unfolded differently.

Porzingis has made sure the Knicks never will.

“This league’s all about situations,” Cauley-Stein said. “I went to a situation where I’m playing behind the best center in the league [DeMarcus Cousins], or I could’ve gone to somewhere where they don’t have a guy, and now you’re the guy, and you’re getting all the touches. That helps a lot.

“You get a chance to get the ball every time, you’re gonna do better quicker, and you’re gonna gain experience faster. He’s very comfortable. … When you can take all the shots you want to take, when you want to take them, and make plays, it’s very hard to fail.”