DETROIT — Knicks rookie center Jericho Sims has made two NBA starts and is perfect in those games — at least where his field-goal percentage and won-loss record are concerned.

In victories at Charlotte and Miami, Sims went 8-for-8 from the field for 16 points and the Knicks went 2-0 with him taking the opening tip.

“He’s been terrific since the summer,’’ Knicks coach Tom Thibodeau said. “Just the way he approaches things. I think he’s growing, he’s learning, he puts a lot into it every day. And I think playing has been helpful for him, but it’s his preparation I think that’s helping him the most. He’s a lot more confident.’’

So far, so good for the experiment that began following the All-Star break and is picking up steam as the Knicks prepared to face the Pistons at Little Caesars Arena on Sunday afternoon.

While starting center Mitchell Robinson didn’t play against the Hornets due to a sore back, the longest-tenured Knick made his return against the Heat on Friday, but Sims still started.

Asked why he kept Sims in the lineup, Thibodeau said, “Because I could,” then laughed.

The Knicks can offer Robinson a $55 million contract extension by June 30. If he becomes a free agent, the Knicks probably will lose him.

Thibodeau said he wasn’t sure if Robinson was 100 percent Friday, but it is evident Knicks brass is eager to give Sims every chance to show what he has with the Robinson decision looming. Sims averaged 27 minutes in the two starts.

Give Knicks general manager Scott Perry and assistant GM Walter Perrin a ton of credit for selecting Sims at No. 58 in the draft last July when some in the organization want to trade the pick for a future selection.

Sims is an active, high-flying, athletic 6-foot-9 center who rebounds well and has an instinctive touch around the basket. He played four years at Texas, but still is learning the nuances of offensive sets and can be hesitant on defense.

“When Sims learns how and when to disrupt shots he’s going to be tough,’’ one NBA coach told The Post. “But they need a big that can stretch the floor.’’

That is not Sims’ forte — nor is it Robinson’s or Nerlens Noel’s. Taj Gibson has developed a 3-point shot, but he’s 36.Because of Sims’ lack of a mid-range game, he is projected as a career backup by some scouts — which still isn’t bad for a 58th selection.

“Other than a natural thing, just his hard work, his energy, his burst, his foot speed,’’ Gibson said of Sims. “He can guard multiple positions. He’s super athletic. But the main thing is he wants to learn. You don’t have to ask him to come into the gym. You don’t have to worry about him being in the gym at a certain time.

“He wants to learn. He asks me questions. But he’s real quiet. He has the long mentality. I’m happy that he’s getting reps, just trying to keep him focused, keep him locked into the game, and learn the team and find ways he can help be effective.’’