TORONTO — Nikita Zaitsev sees no reason why he should be intimidated by the National Hockey League.

"I'm not 17-years-old so why I should be scared?" the 25-year-old defenceman from Moscow said defiantly, citing his extensive KHL and international experience.

The oldest and least heralded of Toronto's rookie crop plays with a steely swagger that belies his limited NHL experience. For example, Zaitsev is eagerly a awaiting a rematch with Sidney Crosby despite a recent humbling at the hands of the Penguins superstar.

"He plays hard and he doesn't really care about what other people think and that's a good thing," said teammate Leo Komarov.

Komarov didn't think that had anything to do with Zaitsev's age or history of overseas play.

"I think it's just the way he is," Komarov said.

Signing a one-year contract with the Leafs in the summer, the undrafted Zaitsev had apparently been getting ready to play in the NHL for some time, preparing himself mentally for nightly tests against the stars he'd spent so much time watching at home in Russia. Teammates believe his strong self-belief compliments his talents.

"He knew he could step in and be effective," fellow defenceman Connor Carrick said. "And at the same time, the reason he's confident is he's got a really strong skill-set."

A strong skater with suave puck skills and good size (six foot two, almost 200 pounds), Zaitsev has quickly risen to the Leafs top defensive pairing, already taking on almost 22 minutes per-game, third most among NHL rookies. His seven points (all assists) are also tied for third among first-year defencemen.

Leafs coach Mike Babcock knew he liked Zaitsev before the season got going and had an idea of how the rookie might be able to contribute, but wasn't certain what he'd get from a player used to a foreign league, bigger rink and entirely different world.

"I didn't know he was going to be a pro like he is," Babcock said.

Specifically, Babcock said, Zaitsev is "way more competitive than I could have hoped."

Witness his testy front-of-the-net battles with Ryan Johansen on Tuesday night. Or his hard check of P.K. Subban into the end boards. Or his jawing with Filip Forsberg. Or a confident drive down the left side of the ice, his backhand attempt on Predators goalie Marak Mazanec requiring a crafty shoulder save.

Zaitsev played more 22 minutes against Nashville in Toronto's 6-2 win and while he and Morgan Rielly struggled some against the Preds' top line, the duo ultimately weren't scored against.

Things didn't go quite as well against Crosby last weekend.

The Penguins captain proved a handful for Zaitsev and Rielly, notching a pair of points in Pittsburgh's 4-1 win over the Leafs. Shot attempts were 21-7 for the Penguins when Zaitsev was on the ice against the game's top player.

"With a guy like Crosby you should be concentrated all 60 minutes when you're playing against him," Zaitsev said. "That was a lesson for me too."

Zaitsev wouldn't say what the lesson was though because the Leafs play the Penguins two more times and Zaitsev didn't want to divulge secrets.

If impressed by Crosby, Zaitsev also had little interest in heaping praise on his opponent. He was still bothered by questions about Crosby from days earlier, his impatience on the subject hardly becoming of the typical rookie.

"Of course, he's the best player in the world," Zaitsev said of Crosby. "Everybody knows it. Me too. I know that. But I don't want to (be) asked about that."

Zaitsev didn't really want to talk about his progress in the NHL either, though he claims to be pleased generally. He said nothing about the NHL has surprised him so far.

Evidently, there were some struggles though at the outset with both Zaitsev and Babcock arriving late to training camp following appearances at the World Cup of Hockey. Zaitsev recently told Babcock that for the first five games of the season "he didn't know one thing I was talking about...which is reasonable."

Babcock added: "Not that the English language is new to him, but it's just a new language of hockey and the way you explain things and so I think that's been an adjustment. But he's a real good player for us."