Blame Andrea Bargnani.

Why not? There’s no one else left. The Knicks faced the Raptors Sunday night — which reminded everyone Bargnani is still on the roster, still stealing James Dolan’s money.

Late Sunday night, when the media was let into the Knicks locker room, Tim Hardaway Jr. marched out, hurling an expletive. At least he cares.

The Raptors went from perennial lottery participants with Bargnani to likely two-time Atlantic Division champions without him. The Knicks went from 2012-13 Atlantic Division champions without Bargnani to a league laughingstock with him.

It’s funny how “addition by subtraction’’ works.

Bargnani watched the Knicks collapse famously in overtime from the bench, in a black suit. That’s appropriate since he’s been the black cloud over the franchise since he got here. The Knicks fell to 5-21 with a 95-90 loss to the 18-6 Raptors after shooting 1 of 8 in the extra session, hearing boos in the final minute.

On this night, Carmelo Anthony tried to play facilitator, eager to move the ball, eschew shots. The Knicks added a new wrinkle to the offense, some pick-and-roll to the triangle. But the players said it was just a different mechanism to get into the triangle and it’s not being abandoned.

Either way, Anthony has nobody to pass to, especially now that J.R. Smith has a lingering heel injury and Iman Shumpert served the first game of a three-week sentence due to a dislocated shoulder.

So now Bargnani is needed even more and he couldn’t be more invisible. He still could be a shotmaker. Counting last season, Bargnani has missed 66 straight regular-season games with either a torn elbow ligament, hamstring strain or calf strain.

He’s making $12 million this season, so figure the black suit he wore on the bench Sunday night is top of the line.

Anthony finished with 34 points, nine rebounds and three assists and forced overtime with his lefty layup with 28 seconds left. He went cold in overtime — 0-for-3 with one turnover. At least he’s out there on his bum left knee, giving everything he has on both ends the past two games.

Coach Derek Fisher sounded like he’s taking a deposition when asked about Bargnani nowadays — which is becoming less frequent. Any chance of the big Italian practicing this week?

“Until he practices, I can’t say what I expect,’’ Fisher said before the game. “When he’s at practices and he’s out there, that’s when it will be. It isn’t a situation where we’re counting the days. He is progressing but we saw what happened last time. I’m not ruling it in or out. When it happens, that’s when it will happen.’’

A lot of things had to go wrong to contribute to the Knicks’ fall from that 54-28 Atlantic Division-title-winning season of 2012-13. And it started with dealing for Bargnani. We’ll still be hearing Bargnani’s name long after he’s gone, with Toronto holding the Knicks’ 2016 first-round pick for a player who contributed to a losing culture that team president Phil Jackson hasn’t been able to reverse.

Power forward Jason Smith has not been a steady replacement and was absolutely awful last night, going scoreless, throwing away passes and missing shots. Not a signing that looks good so far on Jackson’s résumé.

Ironically, Monday is the first day Jackson can ship Smith, as all free agents and draft picks signed in July can have their contracts moved.

Jackson thought Bargnani would be a key cog in the triangle because of his perimeter game. There have been many disappointments to this season — the lazy defense more than the triangle — but not having Bargnani at all has privately flustered Jackson.

With his expiring contract, Bargnani should have all the motivation to come back as he hits free agency.

Now it looks like only a European team will be interested.

Jackson has expiring contracts he’d love to deal to a team looking for cap space or an instant jolt. But there’s not a lot Jackson could take back that coordinates with his master plan of preserving cap space for 2015-16.

Of all his challenges, Fisher has another one. With so many players on expiring contracts, why would they buy into an intricate offense they just have to forget about next season. And the equal-opportunity triangle doesn’t enhance offensive stats. Maybe that’s why they may be departing slightly from it.

“You have a number of guys that are thinking about how they’re going to provide for their families and where their career is going and whether they’re going to be here or on another team and all the ramifications of those decisions,’’ Fisher said. “On top of that they’re being asked to sacrifice more and do less in order to win, so it’s not a great combination for cohesion and team chemistry. But I do think there are enough guys in the locker room that want to do it the right way.’’

As a lost season progresses, that won’t be the case.