Chelsea boss Enzo Maresca says it is "not normal" for a player to make the 16-hour round trip to Kazakhstan for Thursday's Conference League match and then play on Sunday night against Brentford.
The Blues face an eight-hour flight for the 3,700-mile (6,000km) journey to Almaty, in the south of the country, where they will play Astana because of renovations to their home stadium in the Kazakhstan capital 600 miles away.
Chelsea will land back in London on Friday morning, before preparing to face Brentford in the Premier League at 19:00 GMT on Sunday, with the Blues currently second place, four points behind Liverpool.