Chelsea midfielders N’Golo Kante and Ruben Loftus-Cheek will miss the club’s pre-season tour of the United States because of their Covid vaccination status.
The Blues travelled to Los Angeles on Saturday for a training camp.
But travellers who are not fully vaccinated against coronavirus are not allowed to enter the United States.
Currently only US citizens are allowed to enter the country if they are not fully vaccinated.
“N’Golo Kante and Ruben Loftus-Cheek will not travel due to their Covid vaccination status,” Chelsea said in a statement.
Chelsea are due to play three pre-season friendlies in the United States.
They face Mexico’s Club America in Las Vegas on 17 July, Charlotte FC at their Bank of America Stadium on 21 July and London rivals Arsenal in Florida on 23 July.
Ben Chilwell and Callum Hudson-Odoi, who were both injured for long periods of last season, have been included in the squad.
Also travelling are returning loan players Conor Gallagher, Billy Gilmour, Ethan Ampadu and Michy Batshuayi.
The Blues said Armando Broja, who impressed on loan at Southampton last season, will “look to join up with the squad next week”.