This is the center of most importance when it comes to winning the Cup in the NHL. Teams that are deep at center, even if they do not have what would be considered a true number 1, elite level player, are the teams that are most often in the final 4 and competing for the Cup. Certainly it helps to have that elite top of the line player, but it is not mandatory when you are deep like Boston was when they won.
A few notes: this is my ranking where they stand now in the overall picture for the Sabres, which is why in some cases you will see NHL level players either at or near the bottom. I will note at which player I believe the dropoff in being an impact player at the NHL level resides. I will also note a player below that level that can be a wild card.
On to the rankings.
1 Zemgus Girgensons - the clear number 1 at center, at this time; if he ends up as 3rd best to numbers 2 & 3 below surpassing him, that is great news for the Sabres, even if they don't land McDavid or Eichel
2 Mikhail Grigorenko - has turned the corner, so it seems, as far as work ethic and getting it; can he reach his true potential that would match his lofty skills?
3 Sam Reinhart - the only reason he is behind Grigorenko right now is because Grigorenko is playing against men and playing well; 2 & 3 are interchangable; if he ends up being Bergeron, it's a huge success
4 JT Compher - seems to be very similar to Ryan Callahan in every way with how he plays; even similar in build, likely position will be a wing in the NHL with the Sabres center depth (especially if they land one of the big 2 in the draft)
5 Connor Hurley - could be the power forward the Sabres have been looking for, with speed, much like Chris Kreider for the Rangers; must fill out/gain muscle to get there, he too will likely end up as a winger in the NHL
DROP OFF HERE
6 Tyler Ennis - he is the wildcard, but only in terms of making an impact as a winger and not a center as the team has too many better center options currently not too mention if they can draft one of the top 2
7 Tim Schaller - while projected to be a shutdown 4th line center, he is showing that and much more so far this year; possible Gaustad type with more speed and offensive punch; the kind of player you need in your bottom 6 to win
8 Johan Larsson - can be a pest, as shown in NHL stints; best chance is as winger on either 3rd line or more likely 4th line charged with shutting down top end opponents while chipping in offensively
9 Eric Cornel - strong skating, big bodied, 2 way forward, and I say forward as he will be best suited as a W who can fill in at C when needed, the Murray type, he is also a wildcard
10 Torrey Mitchell - his recent play has been very good, and he is all that you want as a 4th line forward that can play 3rd line minutes when needed; truth is there are others in the system that will take his place when the time comes
11 Cody Hodgson - where does he fit? certainly not at center with his poor at best defensive play, seems disinterested on the ice when things are not going his way despite strong work ethic in the offseason; likely trade bait?
12 Kevin Sundher - a C/W that looks to be a depth player at best
13 Cody McCormick - will be gone by the time the team is ready to compete, good soldier and a cap space filler
14 Justin Kea - all his skills are based on hard work and effort; probable 4th line/depth player that will shuttle between AHL & NHL, at best
15 Sean Malone - another potential bottom 6 player, which the team has a lot of in prospects, logjam
16 Chrisopher Brown - solid to strong skater who has scoring ability, but how high is his ceiling is the question, could surprise?
17 Colin Jacobs - at 20, he is a long range project as he has never had an overwhelming ability to score and the Sabres have plenty of players of his like that play a similar game
18 Phil Varone - he may only be 23, but his position as an AHL scorer as his limit may already be set, FA pickup
19 Zac Dalpe - despite NHL time logged so far, seems best served as an AHL player
20 Luke Adam - he is a winger and likely a career AHL player
The top 3 is quite strong if you believe in Grigorenko and the changes he has made, and the next 2 have high upside even though that may be on the wing. The next four in Ennis, Schaller, Larsson, & Cornell all have upside even if that ends up being as wingers. The team has talent at this position. A top 2 pick in 2015 will put them over the top, but they may not even need that pick.