Well there are no 50 man rosters in the NHL, but I guess what you are saying is that you dont think he is a very good player and the bolded portion definitely backs that up which is fine thats your opinion I just dissagree. But I do have to ask you about the bolded portion of your post. Why? Please give a good reason as to why you would possibly think this? Centermen can swing to the wing and given the injury to Pageau it has made Tierney irreplaceable this season. Tierney is an incredibly intelligent player that makes the right play almost every time and is really good at finding his wingers. They need Tierney and Pageau to be the 2 and 3 centermen on this team. White plays just as well if not better on the wing so if all of them are healthy then White swings to the wing.
Center depth is the most important position to have depth in. I really just cant wrap my head around why you think they have to trade either. In my opinion Tierney has come in and thus far been a better second line center than both Zibanejad and Brassard were he is better defensively than both of them and uses his teammates better. No he isnt flashy but he sure is efficient.
I tell you why. Pageau and Tierney are very similar player in terms of skill level and their roll on the team. They are both too good to be on the 4th line and quite not as good to be a genuine top 2 center. If White continues to develop and produce, then where do you slot in Tierney and Pageau. I'd rather move one of them to get a good return(if that is possible), then have them move to wing. We have a lot of younger natural wingers who can do that.
My point is simple. Both are natural C, smart, defensively reliable and can net 40 points. So, use one of them to improve our number 1 need, rather having 2 redundant filling in a role that's not one of our immediate needs