Xabi Alonso said he wants players that "feel a desire" to play for Chelsea after Enzo Fernandez was left out of Thursday's League Cup win over Luton.
The Argentina midfielder has been linked with a move to Manchester City, but no suitor has yet met Chelsea's reported £120 million ($163 million) valuation of Fernandez.
The 25-year-old came off the bench in the Blues' 3-2 win over Fulham to give Alonso a winning start to his reign in the Premier League on Monday.
However, the former Real Madrid boss hinted that Fernandez may not be involved against Brighton on Sunday.
"We need to take everything into consideration, players that are in good moments, players that are not feeling that energy to play. For me it's very important that they feel that desire to play and to have good preparation," said Alonso.
"We talked and we decided that (for Luton) it was better not to be part of the squad. He's a top player, there's no doubt about that."
Selling Fernandez would ease the pressure on Chelsea to meet financial sustainability regulations after another window of heavy investment in the transfer market.
Morgan Rogers, Maxence Lacroix, Marco Palestra, Valentin Barco, Pep Chavarria, Danny Welbeck, Emmanuel Emegha and Geovany Quenda have arrived at Stamford Bridge for combined fees in excess of £300 million.
Aston Villa's Emiliano Martinez is also expected to join to replace the error-prone Robert Sanchez as Chelsea's first choice goalkeeper.
There have also been a raft of departures from the club in recent days, with strikers Liam Delap and Nicolas Jackson bringing in nearly £100 million between them.
Alonso, who previously said his bloated squad size needed to be drastically cut, is satisfied with the clear-out.
"We are quite close to the plan that we had. We will see where we finish, if it's fully executed or there are some things still to be done," he added.
"But overall the balance of what we have is going to be good. We need to see how the last few days develop."
