You must be incredibly desperate if you are holding on to Mitchell. He is skating right now with the team and there have been no reports that I have seen that he has taken a step back but until he shows up on the ice, I am not going to believe anything I read. He still has not been sent to a conditioning assignment so what does that tell you.
As for what to expect from him when he comes back. He will start out on the third line. He is either going to center that line or play the wing with Malhotra centering the line. There is of course the uber small chance that he gets moved up to the top 6 but that will only happen if there are injuries.
Should you keep him? How many teams are in your league and how many players per team are there? Who is on the WW. If you are in a 30 team league full keeper that has 20 guys per team, then yes, he is someone you should hold onto. If he is on your 14 team one year keeper that you have listed above, he would be the worst players on your team when you came back and I would say that you could definitely afford to cut him.
8 Team Keeper - Year 3
G,A,+/-,PIM,PPG,PPA,SHP,GWG,SOG,FOW,FOL,BS,W,GS,GA,GAA,SV %,SHO
Start 3C, 3LW, 3RW, 5D, 3Utl, 2G
25 Man Roster, Keep All
C - Getzlaf, Tavares, J.Staal(LW), Duchene, RNH, Crosby
LW - Kovalchuk, Hall, Benn, Hartnell, E.Kane
RW - P.Kane, Seguin, Yakupov, Eberle, OV
D - Keith, E.Johnson, Carlson, Karlsson, Burns
G - Rask, Schneider, Rinne