Chelsea midfielders N'Golo Kante and Ruben Loftus-Cheek will miss the club's pre-season tour of the United States over their Covid-19 vaccination status, the Premier League side confirmed on Saturday.
Entry rules for the US stipulate that all visitors over the age of 18, barring American citizens and other limited exceptions, must be double vaccinated against the virus.
It was unclear whether the two players were unvaccinated or had received only one dose.
"N'Golo Kante and Ruben Loftus-Cheek will not travel due to their Covid vaccination status," Chelsea said in a statement.
Loftus-Cheek tested positive for Covid-19 in August last year while France international Kante returned a positive test ahead of a Champions League group game against Juventus the following month.
Chelsea manager Thomas Tuchel said at the time that did not know how many of his players had been vaccinated and although he had taken the jab, he would not force others to do so.
Full-back Ben Chilwell and winger Callum Hudson-Odoi, who both missed large chunks of last season through injury, were included in the 29-man squad which will play three games in the US starting with Club America on July 16.
Armando Broja, who impressed last season on loan at Southampton and has been subject of transfer speculation, will join the squad next week, Chelsea confirmed.
After landing in Los Angeles on Saturday evening, thee Chelsea squad headed straight for a training session .
Chelsea, who finished third in the league last season, kick off the new Premier League campaign with a trip to Everton on August 6.
Chelsea squad for United States tour
Goalkeepers: Kepa Arrizabalaga, Marcus Bettinelli, Edouard Mendy, Teddy Sharman-Lowe
Defenders: Marcos Alonso, Ethan Ampadu, Cesar Azpilicueta, Trevoh Chalobah, Ben Chilwell, Levi Colwill, Reece James, Kenedy, Emerson Palmieri, Malang Sarr, Thiago Silva
Midfielders: Ross Barkley, Conor Gallagher, Billy Gilmour, Jorginho, Mateo Kovacic, Mason Mount, Harvey Vale
Forwards: Tino Anjorin, Michy Batshuayi, Kai Havertz, Callum Hudson-Odoi, Christian Pulisic, Timo Werner, Hakim Ziyech