#Knicks’ Quentin Grimes finally looks comfortable

LAS VEGAS — Knicks rookie shooting guard Quentin Grimes finally took matters into his own hands, lighting up like neon in Sin City.

The Knicks’ 2021 first-round pick listened to the words of his former Houston coach, Kelvin Sampson. Listened to his mentor during draft prep, Penny Hardaway. Heard from his NHL-playing brother, Tyler. Heeded advice from Knicks executive Allan Houston. And continues to lean on former Knick Reggie Bullock.

After another quiet first half on offense in which he stayed mostly in the corner awaiting passes that never came, Grimes scored 10 of his 15 summer-league high points in the second half of Friday night’s loss to the Pistons. He started to create. He finished 6-of-10 from the field, 3-of-6 from 3. He also had two blocks.

“I’m starting to get real comfortable,’’ Grimes said late Friday night. “The first two games, I didn’t shoot it the way I can. But I hung my hat on defense and rebounding and making plays. Allan Houston told me keep shooting, they’re going to fall. Penny texted me and said you’re a shooter, keep shooting. That’s what you do. That’s what I did today, being aggressive at all times.’’

Showing he’s not just a 3-point shooter, Grimes took off from the baseline in the third quarter and powered in for a layup while getting fouled.

Two minutes later, Grimes drove the ball, the defense collapsed. Grimes faked a back pass to Immanuel Quickley, then fed inside to center Wayne Seldon, who missed the layup but was fouled.

“I had to be more aggressive and assertive when defenses collapse on me and make the right play, trying to get my teammates into the game,’’ Grimes told The Post. “I’m leaning the system every game. [Summer-league coach Dice Yoshimoto] is running the same system as Thibs [Tom Thibodeau]. Just getting more comfortable what we’re doing out there.’’

Grimes thought he’d have Bullock as his teammate, but the Knicks starting shooting guard of 2020-21 signed with Dallas. They share the same agent, David Bauman, and the players still are in touch.

“Reggie told me Thibs loves shooters and loves defense,’’ Grimes said. “That’s the two things I do. He’s giving me advice about defense and my new city, really helping me as much as possible.’’

Through four games, Grimes averaged 9.5 points and 6.5 rebounds, shooting 35 percent but a decent 35.7 percent form 3.

In the first three games, Grimes took just 10 shots per game while averaging 35 minutes.

Sampson told The Post earlier this week that “it’s OK to be a little selfish in summer league’’, noting Grimes is playing alongside Quickley, who is “a shoot-first, shoot-second, shoot-third point guard.’’

Sampson says he thought Grimes, who led Houston to The Final Four in March, had “butterflies’’ in the summer-league opener and will be just fine.

“There’s a reason he’s a first-round draft choice,’’ Sampson said. “He’ll improve. Quentin is going to be a good player.’’

Though Houston and Memphis are college rivals, Hardaway, the Tigers’ coach, worked out Grimes in the lead-up to the draft.

“He knows I’m a shooter — I played against Memphis three times,’’ Grimes said. “[Hardaway] said keep shooting and they’re going to go in like they did today [Friday]. And he feels I can use my point-guard skills and play on the ball. Penny sees the game and he sees how to play for yourself and your teammates.’’

Grimes transferred from Kansas to Houston after one rocky season after being one of the hottest high-school recruits in 2018. He was projected as a one-and-done, but he needed two more seasons at Houston rebuilding his image.

“Credit to him,’’ Sampson said. “He struggled his first year, found his footing his second year and knocked the door down in his third. Had he come out in his first year, I doubt he’d still be in the NBA.’’