He did win the Sir Matt Busby POTY playing CDM, and I remember some crazy statistics where he was compared to Kanté that season, so I'd say he can play CDM. However, the timing to move him to CDM now is not great, and I'd plan a bit differently. Firstly I think he offers much of the same to CDM as Matic, even though he is a bit faster and covers more ground. Secondly, he has in fact been pretty solid at CM under Ole, and I'd give him one or two more seasons there before moving him to CDM when Matic is finished. Yes, I know some are looking for more end product from him or someone else in his position, but his tactical awareness has been great for some of Ole's game plans. Instead of Herrera, I'd go with Fred for CDM, as some have already suggested. With his recent performances, he has shown some of the abilities I'd like from a challenger to Matic. Being quicker on and off the ball than both Matic and Herrera, and with his close control and dribbling, he could offer something new to CDM. Previously, I've been an advocate for giving him more time at CM, but posters suggesting he played deeper for Shakhtar and his improved performances against PSG and Arsenal have made me think that CDM might be a better fit for him than CM. I guess apologies in advance are in order for jumping the gun on Fred. It's only been a few decent performances from him so far, and it's hard to say what kind of future he has at United, and where it'll be on the pitch, but I'd give it a shout that it could maybe make more sense to play him at CDM and find someone else to challenge Herrera at CM, than vice versa.