ORLANDO, Fla. — Sunday at Orlando’s Amway Center, former defensive center Clifford Ray, of Warriors fame, sat behind the basket and barked instructions at rookie center Mitchell Robinson.

Add another former NBA player enlisted by the coaching staff to tutor Robinson — and other young Knicks. Ray attended Knicks practice in Orlando on Saturday to work with the big men and then watched the Knicks’ 131-117 loss as unofficial coach.

Ray was a big banger who played 10 years in the NBA from 1971 to 1981. He knows Knicks assistant Keith Smart, who was head coach of Fort Wayne of the CBA in 1997 with Ray on his staff. Smart and Ray also worked together on staffs in Sacramento and Cleveland.

“Another guest coach with knowledge and information,” Fizdale told The Post. “Get in as many guys who really understand that position.”

“He told me to keep running the floor and if you foul, make sure they’re on top and not down for reaching,” said Robinson, who wound up in major foul trouble in Orlando with four by halftime and five late in the third quarter.

Last month, ex-Knick Rasheed Wallace guested for a few days to work with the 20-year-old Robinson, who didn’t play college ball. The Knicks don’t quite have a big-man coach on staff.

Fizdale also brought in significant Knicks alums Patrick Ewing, Bill Bradley, Bernard King, Walt Frazier and, most recently, John Starks to address the team. Starks talked eight days ago at the Garden before they faced Orlando.

Willis Reed, who lives in Louisiana, was slated to grace the team with his presence in New Orleans on Thursday, but his appearance has been postponed to next month when he will visit New York instead, according to sources.

Other observations:

1. Frank Ntilikina got his minutes in Orlando for his defensive prowess against Terrence Ross. However, he wound up not taking a shot in his first 20 minutes of action. Playing most of the game off the ball, the Frenchman went scoreless with two assists. His lone shot was blocked on a fast-break runner late in the game. Fizdale said the club had enough offense and wasn’t concerned at Ntilikina’s scoreless, almost shotless night.

2. The three-rookie starting lineup excited Fizdale in its debut in New Orleans when it got out to a 22-12 lead after seven minutes. Against Orlando, it depressed him as Orlando stormed to a 28-10 lead. The Knicks’ rookie trio all suffered poor games — low-energy Kevin Knox, ineffective Allonzo Trier and Robinson. Enes Kanter and Noah Vonleh started the second half for Robinson and Trier. Fizdale said he’s just trying to find “consistency” in a starting lineup before he settles in. With Kanter surging on the court and sending cryptic messages off of it, will Fizdale finally succumb to the Turkish big man and put him back in?

3. Trey Burke was a DNP in three of four games leading into Friday’s New Orleans game. He hasn’t stopped scoring since going back to his mentality of attacking the rim. He put up 24 in New Orleans on 10-of-13 shooting and 31 points in Orlando (11-of-20). Emmanuel Mudiay has started at point guard the last two games, but Burke is making a push to return to the position at which he began the season. It’s another case of development vs. winning games, and perhaps the 4-13 Knicks need some wins.