The Red Bulls may have won Tuesday against a lower-division foe in the US Open Cup, but they’re stuck in a three-game losing skid in MLS – and Saturday they have to try to snap that slide against a red-hot Vancouver team they never have beaten (7 p.m., MSG).

“We think Vancouver is very good team. They’ve obviously had a good season so far,’’ coach Jesse Marsch said. “They’re obviously one of the better teams in the league. What makes them so dangerous is their counterattack. They’re very organized, and when they win balls they go forward very quickly and they’re very dynamic with speedy players and creative players.

“Pedro Morales [three goals, team-high four assists] in the middle of it all makes them very sophisticated and smart and clever. Big challenge for us. And where we are right now, a result means a lot to us, so we have to make sure against a very good team we’re ready to have our best performance of the year.”

Where they are is sitting precariously in fifth place in the Eastern Conference after a red-hot start, with just 17 points, the same as sixth-place Columbus. Only six teams make the playoffs, so every loss is costly.

Not only are they winless against Vancouver – three straight ties in 2011-12 followed by a 2-1 loss in 2013 and a 4-1 humiliation in last year’s season opener – but the Whitecaps are sitting second in the Western Conference at 8-6-2 for 26 points.

And the Red Bulls could be shorthanded when they meet: Right midfielder Lloyd Sam is a game-time decision with a groin injury. He’s been their most consistent offensive player, and scored Tuesday against Atlanta before suffering groin and ankle injuries.

“He feels better,” Marsch said. “The ankle, I think is fine. It’s mostly the groin. Yeah, we’ll see.”

It could be fortuitous that wide midfielder Sal Zizzo, out since May with a knee injury, has returned to practice.

New York City FC doesn’t have long to seethe over blowing a two-goal lead in Wednesday’s US Open Cup loss at the Cosmos. They play Saturday at Toronto FC at 7 p.m. (YES2 and 970 AM).

“It’s disappointing obviously to go out on penalties, but the good thing is we have a game coming up so quick,” NYCFC midfielder Tommy McNamara said. “We have an opportunity to get that bitter taste out of our mouth. It’s a blessing in a way because we can focus on this game in Toronto and play so quickly again.”

The Red Bulls-New York City derby game on June 28 is getting moving up to ESPN and they will also add an additional 30 minutes for pre-game.