Although he didn’t take issue with Jeff Hornacek, Kristaps Porzingis said Willy Hernangomez “deserves’’ to be on the floor. Now he’s trying lift his spirits, acknowledging his friend is “frustrated.” Hernangomez, the Knicks young center who has been called a building block by management, has moved out of the rotation, earning a DNP in the home opener Saturday against the Pistons. He only played in garbage time in the season opener. Before and after the game Saturday, Hernangomez admitted he was “mad’’ at the situation and left the locker room grumbling. “I know he’s in a tough spot right now where he wants to play and he worked hard all summer,’’ Porzingis said. “He was on the national team and now he obviously he loves basketball, he wants to be on the floor every moment. I’m trying to talk to him to make sure he has his head up and doesn’t focus on the bad things, but focus on the things he can do better. And that way, prove that he needs to be on the floor, and we need him to be on the floor. And that’s it. So, as a close friend, I’m trying to talk to him and make sure he has his spirits up.” Asked if he thinks Hernangomez should play, Porzingis said, “I think so. He deserves it. But we have a lot of big guys on the floor and I understand everybody’s fighting for those minutes. And not everybody is going to get what they deserve.” Porzingis had his own issues with Hornacek last season, according to sources.