The Potters were relegated from the Premier League under Paul Lambert last term, which reportedly caused unrest in the camp, with midfielder Charlie Adam claiming that former teammate Xherdan Shaqiri was a class above his 'water carrier' teammates.
Speaking to The Mirror, Rowett has revealed that he has had to instil a tougher mental attitude in his players as they prepare for life in the second tier.
"We were relegated last season and quite clearly the balance hasn't been quite right," the manager said. "Certainly dropping down into the Championship that balance has to be readdressed anyway.You have to have to a slightly more robust mentality to the group.
"It is about the team and synergy of the group and when a team hasn't performed to the level you expect it to with some of the players you have, you have to look at that and see why. That is something we are trying hard to address, we want Premier League players that can play in the Championship and have the mentality to get out of it.
"Charlie has said his opinion and I can see why because after some time a club gets to a level in the Premier League. You have to remember they finished ninth three seasons in a row which is a tremendous achievement."
Stoke open their Championship campaign against Leeds on Sunday.