West Ham United manager Sam Allardyce has admitted that it will take a "tremendous effort" from his players to get through their festive double-header.
The Hammers face back-to-back London derbies in a daunting 48-hour period, travelling to leaders Chelsea on Boxing Day before welcoming Arsenal to Upton Park on Sunday.
Allardyce's side have surpassed all expectations in the league so far this season, but he believes that no team has it as tough over the next few days.
"We're enjoying our football this year and we're enjoying our Christmas a whole lot more than we enjoyed it last year," he told reporters.
"But we've got the two hardest games in 48 hours than anybody else. Chelsea away and Arsenal at home in 48 hours is a big demand for us, even though we're on top of our game at the moment.
"Getting through these two games is going to be a tremendous effort by all the players that get selected, and hopefully they will come through for us as they have through most of the season."
West Ham will spend Christmas in the top four of the table for the first time since 1985 following an impressive first half to the season.
