The Knicks' Marcus Morris, left, drives against the Spurs' Jakob...

The Knicks' Marcus Morris, left, drives against the Spurs' Jakob Poeltl during the first half on Wednesday in San Antonio. Credit: AP/Darren Abate

SAN ANTONIO — The lineup intrigue was not the only source of controversy on opening night as the NBA schedule-maker put Marcus Morris against the Spurs, the team that he had verbally agreed to sign with this summer as a free agent only to renege when the Knicks opened up additional cap space and came calling. Spurs coach Gregg Popovich called it unprofessional earlier this summer and didn’t back down — against either Morris or the Knicks.

“What happened, happened,” Popovich said. “So you decide what was unprofessional or not.”

Popovich was upset that Morris backed out of his two-year deal with the Spurs, but also that the team had traded Davis Bertans to make room for him. Asked if both the Knicks and Morris were unprofessional, he said, “Who signed him? I thought it was the Knicks that signed him.

“It’s the Spurs against the Knicks. One basketball game. That’s how I look at it. I don’t have time to get personal or worry about individuals. It’s about how our team performs.”

But Popovich came over to Morris and spoke with him after the game, clearing the air.

"It was a great moment," Morris said. "Going back and like I said in the beginning, me and Pop had open conversations the entire time. And the thing he said to me was don’t allow the media to come in between what we talked about. That meant a lot. I didn’t know how he felt. I spoke to him after I made my decision. So it was good to clear the air and I got nothing but respect for him, Brian Wright, RC [Buford]. They’ve been nothing but good to me during my career."

Robinson sidelined

While the Knicks were still juggling their plans for a starting lineup, one decision was made for them as Mitchell Robinson was ruled out of action for Wednesday’s season-opening game against the Spurs, suffering a sprained right ankle in Monday’s practice. 

“I’m very disappointed,” Robinson said. “This is the first game of the season and I really wanted to play, but accidents happen. (It was on) an offensive rebound. I didn’t get it and I just came down wrong. I didn’t know how high I was.”

Robinson has been wearing a protective boot, but was in sneakers Wednesday morning. He wasn’t saying when he would be ready to play.

“That’s a question you will have to ask the trainers,” he said. “If it was up to me I would, but you have to ask the trainers. It’s all the trainer’s decision. When they say I can come back is when I can come back.”

Roster filled

The Knicks filled the last vacant spot on the roster Wednesday by signing Ivan Rabb to a two-way contract. Rabb was waived last week by the Memphis Grizzlies after spending two seasons with the team, including playing briefly under Knicks coach David Fizdale.

The 6-10 forward averaged 5.7 points and 4.3 rebounds over 85 games with the Grizzlies.

Fizdale coached the Grizzlies through the first 19 games of the 2017-18 season and Rabb appeared in just one game in that time. 

“Good kid. Hard worker. Really skilled big,” Fizdale said. “Rebounds the ball well. High IQ player. It’ll be good to get back with him and see if we can develop him.”