i agree for the most part but it´s simply a fact that allegri knows more than we do ^^. quite often i read posts like "ah tevez looks tired, let´s bring on coman."
and most of the time that´s solely based on tevez playing badly

. we actually know pretty much nothing about player fitness etc. while allegri can simply ask the player and/or get an assessment from the medical team (at least before and after games).
i would like to see more of coman but often other subs just seem more important:
one sub is pretty much reserved for llorente <-> morata or vice versa. big guy for big guy. i think that´s fine because both aren´t really on the top of their game and definately need their playing time.
the second sub is mostly used for one of the midfield four. one of them is always pretty much wasted after ~70min.
so most of the time there is only one sub left late in the game to cope with injuries, fatique, players on the verge of being sent off etc... not easy to squeeze coman in there.
BUT two things i don´t really get:
- why not bring on coman instead of giovinco yesterday?
- why not use the second sub i mentioned for coman for pirlo/pogba/vidal/marchisio/pereyra more often and move him behind the strikers? that´s supposed to be his best position, isn´t it?