It is clear Koeman treats Ross exactly like any other player. He demands attention, hard work, improvement. Ross is seen by our new boss as ANO player not the golden child.
In fact I'd argue Koeman has been far harsher on several others. Niasse is the most obvious but Mirallas, Jagielka, Robles, Stekelenburg and Funes-Mori were all sent to the doghouse at various times. Mirallas responded well enough to earn a new contract. Jagielka regained his place and showed a big improvement. Stek and Robles both got yanked after a couple of bad games. No sentiment. No favouritism. It is who Koeman is as a manager. Perform or I'll pick someone else.
Ultimately Robles, Ross & F-M all remain too inconsistent to be automatic starters. They also all had obvious sulks. As a consequence they are now seen as squad players. Useful but expendable if the right offer comes along. That is fair enough for me. I like Ross. His talent is obvious but he's unreliable and I wouldn't build a team around him. I wouldn't want him in the starting line up in August based on his form last season.
The only people treating him differently are the fans who cling to him as one of our own and make excuses for him.