Former Stoke City winger Matthew Etherington has told current manager Mark Hughes to be careful as he ponders the sale of Asmir Begovic and Steven N'Zonzi.
Both players have a year left on their current deals, but have been reluctant to sign new ones as they reportedly seek a move to play European football.
N'Zonzi is understood to have caught the eye of La Liga side Sevilla, while Begovic is reportedly being chased by Chelsea, but Etherington has told Hughes that he has to keep the right type of players in his squad.
He told The Sentinel: "There has always been a strong core of players at Stoke and the manager has to be careful. You don't want to be getting rid of too many players from the core at the same time and clearly there is a danger of that.
"God forbid Stoke go on a bad run at any time next season, but if they do, it's players like these you would look towards to turn things round.
"I know new players will come in and replace them if they go, but will they be of the same character and reliability? That's what the manager has to aim for, but I'm sure he knows this."
The Potters finished ninth in the Premier League last season.