I steered away from doing a roster prediction in hopes that I wouldn't have jinxed anything, but since it does not look like Maurice is interested in changing anything, I might as well post the lines as I would like them to be. We'll work from the net out, and going from the bottom to the top.
The situation in the crease is pretty obvious. Or is it? We have two goaltenders who should be able to easily split the starter job, and to be honest, I am not convinced that based on recent performances (before the Leafs catastrophe, mind you) one would deserve the starter position over the other. I am expecting that the workload will be split fairly evenly between our duo, but as it is more likely, Mason gets the edge over Connor until proven otherwise. That being said, if Helle is playing great, Mason immediately becomes the one warming the bench.
Mason
Hellebuyck
Our defensive pairings will largely depend on which guys have chemistry between each other. That complicates making this post this soon, as we have not seen enough to properly judge the players' ability to work as pairs. (this is going great, I know) With a deep and experienced blue line, we should be able to experiment throughout the year, but as of now, I would begin by slotting Myers in the 3RD position. This is absolutely an overkill, and an expensive one too, but we are fortunate enough to afford such a luxury. Provided that he stays healthy, Myers should be one of the four guys who take care of the PK, and if necessary, the second PP unit as well (I, for one, would prefer us having 4F-1D in both units). Myers should be partnered with Enstrom. I have little confidence in Enstrom being capable of handling tough assignments and/or high minutes. A 3LD spot takes some of the burden off his shoulders, while leaving him with a decent partner in Myers. Enstrom could be used as the fifth PKer (or fourth, should it be too hard a job to trust Morrissey to do that) out of the D corps.
The second RD is Byfuglien. I wanted to see him being utilised in this position last year, but the lack of a viable bottom pairing made that impossible to pull off. To go more in-depth with this choice, we all know that in the end, the blue line depends on Buff. No one comes close to being the game-breaker Byfuglien can be - for better or for worse. Another thing we know is that Buff will not be going anywhere, hence why the blue line and its deployment should be done in a way that specifically allows Buff to excel. As his partner, I want to see Kulikov. He would be there to stabilise the pairing - in this instance, Buff must be given a lot of freedom, and Kulikov might be the best LHD of ours to compliment Buff. For these two, it is all about letting Dustin run the show offensively. As for special teams usage, Kulikov is not going to see any PP time, but he is the one to rely upon on the PK. Byfuglien, on the other hand, remains as the lone first PP unit defenseman, but from now on, he should see absolutely no time on the PK, as opposed to the ~3 minutes of PK a night he played last year. We can afford to use the other five guys on the kill, so how about not tiring Buff out there and letting him concentrate on the side of the game he knows best?
At this point, the bottom pairing is blatantly obvious. Trouba is the 1RD, partnered with Morrissey on the left. We all know what these two are capable of: terrific defensive play with little mistakes all around. Trouba has proven himself to be capable of driving some offense, and Morrissey is yet to show his full arsenal - if there is some untapped offensive potential, we could have a very good all-around first pairing that ticks most, if not all boxes in regards to what a high-end pairing should provide in today's NHL. In this lineup, however, these two are the ones who are used to against the best opponents and log a lot of ES minutes. With the second pairing being built specifically for Buff, this pairing has to compensate for the lack of defense. On a positive notion, Jacob and Josh are more than capable of doing just that. Trouba would also play a lot of special teams - he is a lock for the second PP unit, and carries the first PK unit. Morrissey should realistically challenge Myers for the third D spot on the PP, and he should easily be a integral part of the PK.
Morrissey-Trouba
Kulikov-Buff
Enstrom-Myers
Now we get to the interesting part. The fourth line is one we have already seen, and for a long time too. It is formed by Matthias, Lowry and Armia. That's it. The trio is good defensively, which is not even debatable. There is a catch, though. Given how well they play together, how do you split them up? The results have not been pretty whenever someone else has replaced one of the three (this has been rare, though), so I think it is just logical to keep them together and put them in the position in which they are much more suited than where they are currently used: the fourth line. Their lack of offense does not shine through that much when their minutes are more limited, and with them off the third line, we can actually have an offensive third line that adds scoring on its own. This line is a prime candidate to take on some of the heavier assignments, as it has done in the past. As for the special teams, Armia and Lowry are still likely to have a huge role in our PK, but I really don't want to see Lowry on the PP (if he has to, the second unit, please.)
Now, the top 9 has the current top 6, with three added players to fill out the three lines. The three most likely ones to fit the bill are Copp, Dano and Petan. No Connor as of yet, but he will get his chances. To construct the lines, I'm going to take a page out of Garret's book and make sure that the three playdrivers are separated, which puts us at...
XXX - Scheifele - XXX
XXX - XXX - Wheeler
Perreault - XXX - XXX
The way I would go with this is putting Laine with Scheifele, Petan with Wheeler and Little with Perreault. We all know how deadly a duo we have in 55 and 29 - it would be insane to pass up on that. Little and Wheeler has been a very fine combination in the past, but I reckon having Perreault and Little as a duo would give us at least somewhat respectable line in our own end. Then again, it comes with a tradeoff of having Petan centering the second line, but there are quite few options available for us. No matter what we do, with both Armia and Lowry in the fourth line leaves at least one of our other three lines lacking defensive prowess. Anyway, now we have...
XXX - Scheifele - Laine
XXX - Petan - Wheeler
Perreault - Little - XXX
I doubt we need Ehlers in the first line. In fact, I would give that spot to Dano. I feel like he could be a net-front guy in this line, for Scheifele and Laine have much more to give in other ways. The second line LW spot is Ehlers'. I have to admit - I have my doubts about this line, and I don't quite like it myself. Then again, the guys have deceptively good shots and are all gifted with the puck, so it's not horrible. They need sheltering, though, for there is barely any defense between the three, and Petan is unproven as a center, which could cause massive problems defensively. This leaves Copp, who then goes in the 3RW spot. With Perreault and Little helping out, that's a line you can rely on in all three zones. We end up with...
Dano - Scheifele - Laine
Ehlers - Petan - Wheeler
Perreault - Little - Copp
Matthias - Lowry - Armia
Morrissey - Trouba
Kulikov - Buff
Enstrom - Myers
Mason
Hellebuyck
I really can't say anything about the special teams - I simply do not know enough about the possible setups to give credible opinions on the matter.