MIAMI — Mitchell Robinson said his minutes limit was “supposed to be about 18” after his encouraging season debut Friday night.

The center instead logged 12 in Memphis, including half in the first quarter because Karl-Anthony Towns picked up two quick fouls.

“[The limit] goes up,” Robinson said. “[Friday] was just 12. I think it was supposed to be about 18. But 12 is fine.”

Robinson’s limited minutes were certainly enough to alter the rotation.

Precious Achiuwa, who had averaged 31.1 minutes in the previous 12 games, only played four in the Knicks’ win over the Grizzlies.

Robinson also played two defensive possessions in the final 24 seconds after subbing out Towns — a glimpse at how coach Tom Thibodeau will handle the end-of-game rotation in close contests.

“[It shows Thibodeau] trusts me,” Robinson said. “I had been out 10 months and put me in a big possession to get a stop, it shows that he trusts me. He still rocks with me.”

One thing Thibodeau didn’t try Friday night was playing Robinson and Towns together.

The Knicks still have an open roster spot and are able to sign free agents to standard contracts while remaining under the second apron.

The pickings are mighty slim, however, with the top buyout market free agents already scooped up by other franchises.

If a player is waived after March 1 and hits free agency, he’s no longer eligible for the playoffs. So there won’t be new players available from other teams. The market is set.

And for the Knicks, there’s less of a need for reinforcements with the return of Robinson.

But their G-League affiliate in Westchester picked up a recognizable name, announcing Saturday it signed 2022 No. 10 overall pick Johnny Davis.

Davis, a 23-year-old guard out of Wisconsin, was waived by the Grizzlies after becoming a draft bust with the Wizards.

The Knicks are unlikely to face Andrew Wiggins and Jaime Jaquez Jr. in Sunday’s game against the Heat, who listed both as doubtful in the injury report with sprained ankles.

Miami (28-30) beat the Pacers on Friday night.