Fullback Marcos Alonso is among senior players training with the academy squad this week.
Alonso has been pushing for a move to Barcelona, though the deal is stalling due to Barca's problems about registering players under their wage cap.
The Mirror says Alonso, Billy Gilmour, Ross Barkley and Abdul Baba Rahman were all seen training with the academy squad. All four have failed to make any of Chelsea's three matchday squads in the Premier League so far and have been heavily tipped with moves away from the club.
Along with Alonso, Gilmour is interesting Everton, while Reading are eyeing Baba Rahman.