Damyean Dotson threatened to wear his Houston Astros cap to Friday’s game if his hometown team is in command of the ALCS against the Yankees. For now he’s just happy to put a Knicks jersey back on.

On the five-month anniversary of his shoulder surgery, Dotson was ready to make his preseason debut Wednesday at the Garden, even if he didn’t get on the court in a 100-96 loss to Atlanta amid a crowded competition at shooting guard.

Dotson finished last season as the starting shooting guard and also with an undetected labrum tear he likely played with for a few months. His mid-May surgery was a shocker as Dotson didn’t have an MRI exam until weeks after the regular-season finale.

“I never felt anything was torn,’’ said Dotson, who missed two games with a sore shoulder in January. “When I stopped working out [after the season], I felt kind of weak.’’

Dotson — in a sling for five weeks — wasn’t able to shoot for three months. When training camp opened, the Knicks announced he’d miss the preseason. But he returned quicker than expected and participated in scrimmages the past couple of days.

“My stamina is there,’’ Dotson said before the game. “Of course there’s going to be a little rust but just got to find my rhythm. It was a long summer.”

The well-built, 6-foot-6 Dotson showed 3-and-D potential in his second season after a throwaway rookie year after being a Phil Jackson draft choice. The second-rounder from Houston now has to battle for minutes after the club signed veteran shooting guard Wayne Ellington, drafted rookie RJ Barrett and still has Allonzo Trier on the roster.

Frank Ntilikina, along with Dotson the longest-tenured Knick, also can play the 2.

“It’s been like that since I’ve been here,’’ Dotson said. “It’s always been stacked at the 2-guard. I compete every day and bring it. ‘’

Dotson averaged 10.7 points on 37 percent 3-point shooting. But he finished the season shooting 30 percent in his final four games. The Knicks still didn’t give him an MRI exam after the exit interview.

“I just thought I was tired,’’ Dotson said. “My legs were tired and I couldn’t make a shot anymore.”

While Dennis Smith Jr. started at point guard as expected, David Fizdale pulled off a surprise in putting new signee Bobby Portis in the lineup over foul-plagued Mitchell Robinson at center. Portis scored 16 points alongside new frontcourt-mate Julius Randle.

Robinson, the Knicks’ second-year center, picked up five fouls in 10 minutes. Fizdale said the move wasn’t to protect Robinson from foul trouble. He wanted to see the Portis-Julius Randle frontcourt tandem — not to punish Robinson.

“That’s going to be constantly something [foul trouble] we’ve got to battle and coach and continue to show him on film, and drill it in practice,’’ Fizdale said. “He’ll have some days where he still gets in foul trouble, but I think those days will start getting where he doesn’t. I want to just look at different pieces and how they fit. I want to see how [Portis] looks next to Julius, maybe open up the floor a little bit more for RJ [Barrett] and Dennis. We’ll see how he reacts.”