In a game he saw as a measuring stick, they got three shots on net in the first two minutes and looked like they could hang with one of the top teams in the NHL. Then Frazer McLaren took exception to Andrew Desjardins' hit on Jerred Smithson and things fell apart.
McLaren's penalty was the first of many costly ones as the Leafs lost to the Sharks 4-2 Tuesday night at Air Canada Centre, their fifth straight defeat.
"Discipline's a huge part," said Leafs winger Mason Raymond, who scored a goal and committed two penalties. "You're killing penalties, you're not playing offence and you're playing in your own zone, so we're kind of shooting ourselves in the foot there."
Taking ill-timed penalties is often a recipe for failure, and that's especially the case against a high-powered team like the Sharks (19-3-5), who entered the game second in the league in goals per game. But more so than giving them the man advantage, the Leafs (14-11-3) stunted their own flow by going to the box.
McLaren's penalty came not long after the Leafs got the game's first three shots in the first 1:21 and controlled much of the play. Even though the Sharks didn't score on the ensuing power play, they didn't give the puck up much for the rest of the period.
Former Leafs forward Mike Brown opened the scoring for the Sharks midway through the period when he tipped a shot from defenceman Jason Demers five-hole past James Reimer.
"It kind of bounced around a little bit and just squeezed through," said Reimer, who made 37 saves. "I wasn't able to close my legs quick enough. That's just the way she goes."
The lasting effect of San Jose's seemingly never-ending possession was the Leafs trying desperately to catch up. When Jay McClement took a hooking penalty and then Raymond was called for tripping 33 seconds later, the Sharks wasted little time before captain Joe Thornton scored on the five-on-three power play to take the lead.
"Go down five-on-three, and that took the momentum totally for the period in their favour," Carlyle said, making reference in part to a 17:17 shot drought the Leafs went through. "When you give a hockey team like that momentum, they can skate, they're big, there was no real surprise on what they were going to do. They did it. And it took us till the second period before we got our things going."
The Leafs got things going in part because of San Jose's lack of discipline. Raymond scored a power-play goal off the rush 2:44 in, and Phil Kessel was the beneficiary of Logan Couture's high-sticking minor later when he scored on the power play.
Centre Tyler Bozak, who fed Kessel for his 200th career goal and 15th of the season, left the game for good after with what Carlyle called an upper-body injury. The Leafs were already without centre Nazem Kadri, who missed the game with a death in his family.
Carlyle didn't know the severity of Bozak's injury but acknowledged that it hurt against the Sharks.
"For half the game, almost, we were short," he said. "We had three centres. We're taxing a lot of people here right now."
For part of the second period, the Sharks were getting taxed thanks to the Leafs turning the tide.
"I think we maybe got a bit lackadaisical at the start of the second period for about 10 minutes and they really gave it to us," Thornton said." The 10-minute mark it kind of switched. We had a timeout and we kind of flipped it back on them."
Naturally it was another penalty that caused the reversal. The Sharks had started to get more attack time, and when Raymond took a high-sticking penalty, it gave San Jose the spark it needed.
Again, the Sharks didn't have a power-play goal to show for their efforts, but they had enough attack time to put the Leafs on their heels.
At no point was that more evident than on the shift that led to Mark Stuart's game-winner. Toronto's fourth line of McLaren, Smithson and Colton Orr were caught on the ice for 1:48.
The Leafs had chances to clear it, including Morgan Rielly failing to ice the puck, but when they didn't, Stuart skated in and scored his third of the season.
"They're tired and they're fourth line so, no disrespect, but you can maybe try things that you ordinarily wouldn't do," Stuart said. "I think we had a lot of good looks on that shift. We were able to get a good bounce and capitalize on it."
Having the fourth line and a 19-year-old defenceman on the ice for almost two minutes wasn't what the Leafs wanted, but they got some chances to tie it in the third. Ultimately it wasn't enough, and Couture iced it with an empty-net goal at 18:36 of the final period.
"I thought we worked hard out there, I thought the effort and the compete level was there," winger James van Riemsdyk said. "(We made) a couple mistakes. They're a good hockey team, they're going to capitalize on their chances."
NOTES — The Leafs held a pre-game moment of silence for Toronto police constable John Zivcic, who died in a car accident Saturday. ... Cody Franson missed his second straight game with a lower-body injury. Carlyle had called him a game-time decision, but the defenceman did not take part in warm-ups.