Southampton manager Ronald Koeman has labelled his side's Christmas schedule "impossible" ahead of a hectic two days.
Koeman's side takes on Arsenal in Boxing Day's late kick-off, before travelling to West Ham less than two full days later.
Southampton is in the midst of a six-game winless run, but that could quickly become eight if Koeman cannot coax some good performances out of his tiring side.
"It's too much," he said. "It's too much and we have to travel [to West Ham]. The rest between the two matches should be at least 48 hours.
"In our case it's not 48 hours because we play at 7.45 pm on Boxing Day and then on Monday at 5.30 pm.
"Impossible. But okay, we accept it and play."
The busy schedule means Koeman will have to heavily rotate his squad to minimise the risk of injury.
"You can't play with the same 11, it's impossible," he said.
"I was watching back to last year and we made four changes between Boxing Day against Crystal Palace and the Chelsea game.
"I remember some of the players were gone after 50, 60 minutes. I will make more changes to the team this time."