No. You saw him playing in midfield.
You will never ever see him stopping Fellaini or Harry Kane, from winning what would otherwise be free headers.
So therefore one of the other players is filling in for Fernandinho, in every one of those situations, when he is off the pitch. They now have an extra job, each.
I saw him playing at the base of midfield, where Fernandinho plays, I accept his role in that position is different to Fernandinho and that the team adapts to acvomodate that but that is no different to the team adapting to accomodate an inverted left back instead of an attacking full back.
My point is he can fill in there to spare Fernandinho's legs on occasion.