Ekstrand was banned and Casseti retired.
Abdi was rested and FF is mainly sub ATM.
It does seem some are unhappy with Sannino which is a worry this early on.
I would guess players like Dyer aren't pleased not to be starting which is no bad thing but its seem to be more than that.
Training ground issues over tactics and how he works.
Going by Bepe and his antics on the bench I can only presume he works them pretty hard and isn't afraid to say what he thinks which in the era of player power might not work.