TORONTO—Team USA’s margin for error at the World Cup of Hockey has been all but erased after they were upset by Team Europe, 3-0, in the tournament opener Saturday afternoon.

And with an absolutely loaded Canada team up next, it’s probably not a stretch to say the Americans are already in ‘must-win’ mode.

"This is not a marathon, as coaches always talk about in NHL seasons; this is a sprint," Coach John Tortorella said. "We've put ourselves in a spot now where we're chasing. We're chasing the tournament."

James van Riemsdyk was more succinct.

"We have a game on Tuesday," he said, "and obviously that's a must-win for us."

Derek Stepan concurred, adding: "I kind of agree with him; it’s a must win for us. Maybe it’s a good thing that we’ve got our backs against the wall, got a little adversity. We’ve got to up our level and up our game."

USA came out flat and miscues buried them with a quickness.

Just 4:19 into the contest, a pinch by Ryan McDonagh led to a 2-on-1 that Marian Gaborik fired past Jonathan Quick to lift Europe to a 1-0 lead.

Then, at 4:02 of the second period, Patrick Kane lost the puck at the offensive blue line, creating to a 2-0 that ended when Leon Draisaitl dished to Nino Niederreiter, who then returned to the puck to Draisaitl at the doorstep. The goal looked as though it belonged in an all-star game, not a best-on-best tournament.

"I think we're going to be able to chip out some of the glorious odd-man rushes we gave them early on for a couple of freebies," Tortorella said.

Said Stepan of the odd-man breaks: "For whatever reason, our reads were just a step behind tonight."

Kane took full responsibility for his costly turnover.

"On that second goal, I’ll definitely take the fault on that one," he said. "That’s a play that I’ve made a million times in my career. Just kind of lost the puck and the next thing you know they go down 2 on 0. That’s unacceptable from me."  

Late in the second, it appeared as though the Americans would make a game of it after a puck hit van Riesmdyk’s shoulder and Stepan’s helmet and into the net. The goal, however, was overturned after a replay review because it was determined that van Riemsdyk intentionally directed the puck into the net.  

"We're trying to get more goals in the game," van Riemsdyk said. "I thought it should have counted. Goals like that, I don't see why it shouldn't count."

Tortorella added: "When I saw it on the screen [from] the bench, one view I thought he did move his arm to knock it in. But then I looked at another view and JVR just skates into it. I think it's a goal. First of all, no matter what he did it hit Step's helmet before it goes into the net so I think it should be a goal."

The NHL later explained, in part, that the deflection off of Stepan had no bearing on the ruling. 

Although mistakes put USA in a hole, that wasn’t what irked Tortorella the most. He was most bothered by the American’s inability to generate quality scoring chances on Jaroslav Halak, who stopped 35 shots, including all 17 he faced in the final frame.

"You have to give the opposing team some credit here as far as how well they defended, but I thought there were chances where another play was there, it just didn't happen,” Tortorella said. “I thought our guys tried hard. The bench was good. We tried to stay together even through a little bit of adversity there. But we just couldn't create better scoring chances."

In Team USA’s last three games dating to the 2014 Winter Games in Sochi, they’ve been outscored 9-0 in best-on-best hockey.

"We just have to get more determined around the net and get those second and third opportunities,” Joe Pavelski said. “To go back nine periods and we don’t get anything, it’s frustrating. We’ve had some looks along the way. …We got to finish."

The trio of Capitals on Team USA had a mixed afternoon. John Carlson led all American skaters in playing time (22:54) but only directed a pair of shots at the net. T.J. Oshie played on the first unit power play with Carlson and possessed the puck a lot, but he struggled get to his shots through to the net. In fact, he attempted six shots but just one of them forced Halak to make a stop. Matt Niskanen, meantime, might have been USA’s most noticeable player. In 21:48 of ice time, he was credited with seven shot attempts, including four on net, two hits, a takeaway and a blocked shot. He also broke up a 3-on-1 early in the second period with a well-timed slide in the slot.

Washington’s players were not made available to reporters following the game.

So where does Team USA go from here? Well, it pretty much begins and ends with Tuesday’s matchup against Sidney Crosby and Canada, the prohibitive favorite to win the title on home ice. Tortorella could shake up his forward combos and d-pairings, or perhaps insert Dustin Byfuglien, a healthy scratch Saturday, into the lineup. But whatever he decides, it had better work. Because in an eight-team tournament, it can get late pretty early when you drop the opener.

"It's a spot we didn't want to be in," Tortorella said. "It’s a very dangerous spot, but we are here. We just need to stay together and not blow ourselves up here, have a couple of good days of practice and get ready for our next opponent and try to do better."