Joakim Noah’s debut season in New York was so disappointing because it had the potential to be so exciting.

The Hell’s Kitchen native was coming home, the rare free agent of his stature to seek out the New York spotlight. The two-time All-Star was barely two years removed from being named the Defensive Player of the Year, and capable of providing the toughness and intensity of his beloved 1990s Knicks teams, whose posters used to adorn his bedroom walls.

What followed was worse than the worst-case scenario seemed to be — a season plagued by ineffectiveness, injuries and a lengthy suspension. What was even worse was that three years remained on the $72 million contract.

It was easy to imagine how much uglier the deal would look in a year or three, and nearly impossible to envision how Noah could again be the active force who could anchor a defense and energize his team.

But on Saturday, the 32-year-old was running up and down the floor, crashing the boards and hounding Kristaps Porzingis on defense, looking like he rarely has in a Knicks jersey.

Seeing Noah so effective in training camp has even been in a surprise to his coach.

“Coming off those injuries, literally, I’m shocked of how well he’s played just because I didn’t think he was gonna be ready this early,” Jeff Hornacek said following practice Saturday. “I’m extremely happy with how he’s playing. He’s playing the right way. He sets great screens, he rolls hard, which opens up other things for guys if he doesn’t get it. He’s been finishing with driving layups. He’s been playing great.

“He wants to come back and show everybody what kind of player he is and he’s worked hard to do that over the summer. I give him a lot of credit so far.”

Still, Hornacek won’t know if Noah can be an asset until the second week of November since the big man still has 11 games remaining on his suspension, for taking performance-enhancing drugs.

Noah is eligible to play in the preseason, leaving Hornacek with the awkward task of figuring out a rotation with several new players — and a more crowded frontcourt following the acquisition of Enes Kanter — while giving time to a player who won’t be available until the season’s second month.

Noah, who battled shoulder and knee injuries last season, hasn’t seen game action since Feb. 4.

“We’re probably gonna keep him limited, but we want to get him in and taste playing again,” Hornacek said. “He was out the last part of the season, so we want to get him some time, definitely.”

Last week, Noah talked about wanting to redeem himself for last year, and “be at peace” with the massive contract he signed.

With Carmelo Anthony gone, Noah knows his veteran presence could mean even more, playing on a team that filled with young teammates.

“I just know that I have a lot of experience in this game, good and bad and I just want to use that to try and help some of these younger players,” Noah said. “When you go through what I went through and you have a lot of injuries and things like that, you just appreciate practice and competing and things like that. I’m just happy to be here.

“I want to compete. I know I have a suspension but I just want to be a good influence on the younger kids from now on.”