He is well documented as the best defenseman outside the Nhl. He will be playing huge minutes when we get him. Brian McCabe type shot from the point with equal or better mobility.
5 years ago Fabiann Brunnstrom was the best forward not in the NHL. Got a hat trick in his first NHL game and that is still his biggest contribution at the NHL level, which he is no longer playing in.
6 years ago Brayden Schenn was the best prospect in the world and the best player not in the NHL. Since then he has developed into a decent second line forward, but no where near what he was hyped to be.
7 years ago Jonas Gustavsson was the best goaltender not in the NHL. Got shell-shocked and allowed 6 goals to the Capitals in his first career game and has since then become a career back-up goaltender.
Just last year Simon Moser led the KHL in scoring. He came to North America and could not crack the Predators line up and is now back in the KHL.
My point is this, just because Zaitsev is said to be "the best defenseman not in the NHL" does not make him a legitimate first pairing defenseman when he actually arrives in the NHL. Do i hope that he becomes a top flight defender for the Leafs? Absolutely, but until he plays a full season in the NHL i will reserve my judgement on him.