Reece James was a surprise inclusion in Chelsea's squad for the Club World Cup, travelling to Abu Dhabi on Sunday despite Thomas Tuchel saying he would miss the tournament.
A 23-man Chelsea party headed to the finals after Saturday's nervy 2-1 FA Cup win over Plymouth Argyle.
James was not expected to be among them as he recovers from a hamstring injury, with coach Tuchel saying before the Plymouth game the wing-back required "a couple of weeks" before even returning to training.
The Chelsea boss said James would not travel.
With Edouard Mendy to join his club-mates after playing for Senegal in Sunday's Africa Cup of Nations final, the Blues are missing only two first-team players.
Ruben Loftus-Cheek, who is dealing with a minor injury, has not made the journey, while Ben Chilwell's season has been curtailed by a serious knee issue.
For now, however, Chelsea are without Tuchel, who tested positive for coronavirus and intends to link up with his team at a later date.