although im not 100% sure on the role rss played last two games i would imagine to replacew him as a player in the team you couldn't use a winger.
If we bought an alternate in then that answers my query as to who replaces him. Makes the squad more flexible then, although i think early impressions is that ross is to be a pivot in our team from now on. speed outside of him and striker up top, ross is to make the attack play flow which makes him priceless for the tactics.
As I said Ash, Koeman will change the system. We don't need a no.10 in a 4-3-3, per se.