RJ Barrett of the Knicks controls the ball against Reggie Bullock of the...

RJ Barrett of the Knicks controls the ball against Reggie Bullock of the Mavericks at Madison Square Garden on Jan. 12. Credit: Jim McIsaac

DALLAS — The Knicks have spent the season figuring out how to make the roster fit and work together, flipping combinations in and out as they try to understand why they can’t replicate the success of last season.

While fingers have been pointed at the additions to the roster, the answer may lie in the player who was subtracted — Reggie Bullock — who the Knicks faced Wednesday night at American Airlines Center.

Bullock was never the star during his time in New York, a starter but still a role player. He averaged 10.9 points per game last season as a 3-and-D wing, shooting 41% from beyond the arc and taking on the assignment of defending the most dangerous offensive wing on opposing teams.

Bullock and Elfrid Payton were the Knicks' starting backcourt last season, but when the team was ousted easily by Atlanta with the Hawks stifling Julius Randle the team boosted firepower by adding Evan Fournier and Kemba Walker. Bullock signed with Dallas and has stepped in as a full-time starter and is averaging 12.9 points in the last 11 games. No coincidence that the Mavs entered Wednesday night with five straight wins and 11 in their last 13 games.

"Reggie’s going to help any team," Knicks coach Tom Thibodeau said. "That’s who he is. He’s got a skill in shooting; he spaces the floor for your best players. He’s a great defender, and he’s got length. He’s a long wing. Wherever he’s been, he’s always helped the team. He’s a team-first guy, so he’s a good player. He’s been a good player for a long time in this league."

Thibodeau insisted that the Knicks would have liked to bring back Bullock, but even if they had the cap space they seemed to make their choices — signing Fournier and bringing back Alec Burks.

"You know, look, I love Reggie," Thibodeau said. "He’s a good player. When a guy earns the right to free agency, he has to do what he thinks is best for him and his family. I got great respect for him, so I wasn’t disappointed. I know that’s part of the business. For a guy who conducts himself the way he does, you’re always happy when they get good situations.

"So, I think he was a big part of what happened last year and a byproduct of when something good happens like that, everyone’s value goes up, so that’s the case. And then you have to decide what’s best for your organization . . . And hopefully, you can find something, but it doesn’t always work out that way. It’s part of the league."

The Knicks have only glimpsed that sort of chemistry on rare nights and have struggled for an identity, too. Walker, after being benched for a nine-game stretch earlier this season, was shut down for the remainder of the season after the team could not find a taker for him at the trade deadline. Burks has been forced into a starting backcourt role rather than the versatile bench piece he was last season.

"You could start Reggie," Thibodeau said. "You could bring him off the bench. And that’s the great value that we have in Alec. Alec’s built and wired the same way. You can start Alec. You can bring him off the bench. You can play him at multiple positions. Those guys are invaluable in today’s league, guys who can play '2,' '3', '4'. In Alec’s case, he can play the point, as well. So, there’s more of a premium now on those guys than ever before, I think."