The Knicks will get their first glimpse of life without Mitchell Robinson. 

After eight years with Robinson on the roster — though not always on the active list — New York faces the Sixers in Tuesday’s opener with Andre Drummond as the backup center. 

It is by far the biggest change from last season’s championship-winning roster and therefore will be under the microscope when Drummond faces his former team from Philly. 

“Mitch [who signed with the Celtics in free agency] is a great player. We’re not bringing Andre in here to quote-unquote be Mitch,” coach Mike Brown told The Post’s Steve Serby. “Andre’s going to be Andre, but that means everybody else has to give a little bit more defensively, and has to give a little bit more when it comes to offensive and defensive rebounding.”

Drummond’s greatest strength, throughout a lengthy career, was rebounding. But he’s now past his prime at 33 years old and replacing the NBA’s best offensive rebounder in Robinson.

The Knicks entered camp without a third center after Karl-Anthony Towns and Drummond, opening up a competition that ended with James Wiseman as the winner.

Wiseman is a former No. 2 pick and draft bust with the Golden State Warriors, but a superb athlete who always had a fan in Mike Brown. 

Brown was the lead assistant at Golden State when Wiseman was drafted there. 

“It was a different situation with the Knicks,” Brown said. “You come in as No. 2 pick in the draft with Golden State and you’re talented and skilled as he is and it can be tough on you because of expectations. Not just from the media and fans but sometimes your teammates and coaches and rest of the organization and if it’s hard for certain individuals to live up to. … With this situation, it’s — OK, he’s been around the block, he’s experienced adversity. We’re not looking for him to start or fight for a starting position. We’re not necessarily looking for him to come in and be a backup. He has the luxury of growing at his own pace without much pressure.”

The Sixers also have frontcourt questions after their backup, Ariel Hukporti, tore his Achilles in the preseason opener. Hukporti was the Knicks third-string center last season but left in free agency. 

Joel Embiid’s backup is Adem Bona, who will have to deal with Drummond, his teammate last season.