Joao Felix has not travelled with the Chelsea squad for their Conference League fixture against FC Astana due to an issue.
The 25-year-old has been a regular in the cup side selected by Enzo Maresca.
What happened?
Felix came on from the bench against Spurs on Sunday afternoon as Chelsea clinched a 4-3 win over their London counterparts in the Premier League.
He was expected to make the eight-hour flight to Kazakhstan to face Astana in Europe on Thursday.
Why it matters for Joao Felix
However, Felix was not spotted with either group during Chelsea's training at their Cobham base on Wednesday morning.
As reported by Simon Johnson of The Athletic, although it is yet to be confirmed by Chelsea, Felix has picked up an issue.
What comes next?
Chelsea will hope Felix is fit enough to be in contention for selection when they host Brentford in the Premier League on Sunday evening.
Many first-team players have been left behind in England as Maresca rotates his side for the Conference League match.
Mykhailo Mudryk is still suffering from illness and will miss the match.
A whole host of academy stars have travelled, with The Athletic stating that the number exceeds 10.
Marc Guiu is set to return to the Chelsea attack.
Filip Jorgensen will replace Robert Sanchez in goal for the visitors.
On his selection choices, Maresca concluded: "Eight hours is not a normal time for a game, you know, but we have to go there, we have to play, try our best and thinking also about the next game."
Maresca's side will face Astana in the Conference League on Thursday.