Faceoffs aren't the be all, end all for centers, even young ones who may not learn the craft to a tee for quite some time.
Burmistrov's lack of size also doesn't worry me about his future faceoff ability, mainly because he is feisty as it is, which I think in time will really help him in the faceoff circle, I hope so. Sure size helps a bit, but not overly too much in my opinion. Staal and Getzlaf, both big centers, two of the games best, have never been too good in the faceoff circle. So much so that they're lucky to hit 50%.
Eric Staal, for example, not good in the faceoff circle, was quite bad as a younger player entering the league and it carried on into his career. The last couple seasons he's improved a touch and is closer to or above the 50% mark.
From 03-04 to 09-10, Staal hovered around 41%-45% tops all in which he took 1200-1700 faceoffs (aside from rookie season at 669).
Ryan Getzlaf, another who was consistently poor in the faceoff circle for a number 1 center, he has ranged from 44%-47% on average since he entered the league.
Then we have Burmistrov, who just turned 21 four months ago, and in his first 3 seasons in taking 500-700 faceoffs, he's ranged 41%-44%, while thus far this season through just 77 faceoffs he's at 46.8.
Again, Burmistrov JUST turned 21 years old 4 months ago. He is so young, yet shows such good tools here. If and when he can put it together, and at this rate I really don't see why he won't find his rhythm, he could be a special player.