The former Bayern Munich chief has refreshed his squad over the summer with Karim Adeyemi and Anthony Gordon arriving as Robert Lewandowski moved on.
Those moves have put another barrier in front of Roony's path to the starting XI and Barca's ongoing pursuit of Rodri shows Flick's thoughts on Casado.
Spain international Casado is set to join Saudi Pro League outfit Al Hilal on a permanent transfer with Roony tipped for a Serie A move - but that could be as a loan.
Both players were omitted from the squad who travelled to Italy for preseason games against Nottingham Forest and Udinese and Flick confirmed an exit decision has already been made on the pair.
"At the end of each campaign there are changes, it's normal.
"It is difficult, but it's part of my job to have to make these decisions. I spoke with both of them at the end of last season, and also in England, and I gave them my advice."