Chelsea boss Enzo Maresca said it is "not normal" for a player to make the 16-hour round trip to Kazakhstan to then play on Sunday night against Brentford.
The Blues are in action in the Europa Conference League on Thursday against Astana, facing a 3,700-mile journey to Almaty, in the south of the country.
Maresca's side will play at the Almaty Central Stadium, which is 600 miles from the Kazakhstan capital, because of renovations to Astana's home stadium.
Chelsea will land back in London on Friday morning, before preparing to face Brentford in the Premier League, hoping to keep pace with league leaders Liverpool.
"Eight hours is not a normal time for a game, but we have to go there, we have to play, and we want to try to do our best, thinking also about the next game," said Maresca.
The Blues are currently top of the Conference League standings after four games, with Polish side Legia Warszawa the only other side with a 100% record in the competition.
Maresca also said a number of first-team players will be rested for the trip, including Noni Madueke, with Pedro Neto suspended for Sunday's clash against the Bees.
The Chelsea boss also confirmed that defender Josh Acheampong will be handed a first senior start after a breakthrough in contract talks.
Youth players Ato Ampah, Shumaira Mheuka, Harrison McMahon, Kaiden Wilson, Richard Olise and Harrison Murray-Campbell are in the travelling squad.
"The ones that are not involved tomorrow, first of all, they're going to be training, and they have to train well," added Maresca.
"You never know whether we might need one of the guys who play tomorrow on Sunday. Ideally, we prefer not.
"We are going to land at 6am on Friday, and it's not normal for one of them, if they land at 6am on Friday, to play again on Sunday."
"But if we need [them to], they are going to make the effort."
Adding to the long flight, temperatures are expected to be at around minus 11, though defender Axel Disasi was not worried about the conditions.
"We just have to put on two pairs of gloves and be ready to compete in these conditions," Disasi added.
"We all know the conditions of these games, it's an eight-hour flight and minus 11, so download some movies to watch on the plane, be ready to fight and keep first place."