NBA

McGrady plays but struggles in Knicks loss to Celtics

BOSTON — Tracy McGrady decided his bruised left knee was good enough to play through last night. It’s just his game wasn’t good enough.

McGrady doesn’t have only knee problems. He has confidence problems, too, and made that stark admission afterward.

After much discussion, McGrady gave it a go vs. the Celtics after limping off the court in the final minutes of Monday’s loss to the Bucks.

Still battling soreness in his left knee, McGrady looked like a shell of himself, playing tentatively in scoring six points, taking just eight shots. McGrady deferred most of the game at the new Boston Garden, his highlight being eight assists. But that’s not what got him seven All-Star selections.

McGrady still was in position to be a hero late, as he lined up for a 3-point shot from the left wing with 30 seconds left and the Knicks down 3.

But there are no fairytale endings in this Knicks season. McGrady bricked it off the front iron, and the Knicks lost their eighth straight, 110-106, to the Celtics, falling 18 games below .500 (19-37).

“I’m still trying to get my timing and rhythm,” McGrady said after shooting 3-of-8, 0-of-4 on 3-pointers. “Even when I took that shot, I wasn’t that confident making it. I’m not confident on the basketball court as I’d like.”

McGrady dressed only after he and Mike D’Antoni agreed to limit his minutes to the 20-25 range. McGrady had logged 34 and 30 minutes in his first two outings and his knees couldn’t take it after being off since Dec. 23.

“I tried to push through it,” McGrady said. “I really wanted to test it. It was nothing that had to do with my surgery. I banged knees [Monday]. It’s just playing through the bruise.”

“It was on my mind,” McGrady said of sitting out. “I thought about it. I told coach because I played 30 minutes the last two games and this was a back-to-back, I didn’t want to push it. I thought we’d be cautious with it, play 20, 25 minutes.”

McGrady, who logged 26:34, acknowledged he has no legs.

“I found out in these three games, my legs are just fatigued,” McGrady said. “The first half I’m fine. When I come out at halftime, I find out my legs are just gone. When the legs are fatigued, it creates a little soreness. I just got to fight through it. I didn’t labor like I did [Monday] night.”

“Right now I’m really not sold on going out and trying to score 20 or 25,” McGrady said. “That’s not what I’m here to do. That’s not how I’m going to get myself back. Tonight I wanted to be playmaker and make my teammates better.”

D’Antoni admitted it was a tough call to return McGrady back to the game with 5:40 left.

McGrady said he won’t be “100 percent” till next season and doesn’t feel he’ll be in game shape for two weeks.

After falling behind by 14 points in the first quarter, the Knicks made it a contest as the Celtics struggled without superstar Paul Pierce. David Lee scored 28 points and 15 rebounds and Wilson Chandler added 19 to keep it close. And new starting point guard Sergio Rodriguez gave the Knicks a boost with his 3-point prowess, finishing with 18 points, making 7 of 10 buckets.

Of the Knicks’ newcomers, McGrady and Eddie House were the least impressive, while virtual unknown Bill Walker showed flashes.

Though House received a huge standing ovation when he checked into the game in the first quarter, with the Boston fans chanting “Ed-die,” he struggled, missing all five of his 3-pointers and finishing with four points.

Walker, the 6-5 former Kansas State guard obtained in the Nate Robinson deal, made his Knicks debut and recorded two ferocious dunks, including an alley-oop slam in the first half and finished with seven points in 12:42.

marc.berman@nypost.com