Sam Allardyce is wary of West Ham succumbing to fatigue as they start a busy festive period with the visit of Leicester City on Saturday.
West Ham have surprised many with their impressive start under Allardyce this season and are fourth in the Premier League after losing just four of their 16 games.
However, the club's UEFA Champions League credentials will be put to the test by a run of fixtures that sees them play four games in 13 days, beginning with this weekend's encounter with Nigel Pearson's team, who sit bottom of the table.
Allardyce has a near fully-fit squad, with only midfielder Mark Noble unavailable for the hosts due to a calf injury.
However, the former Bolton Wanderers, Blackburn Rovers and Newcastle United boss knows he will have to manage his players carefully if West Ham are to maintain their form.
"We're all looking forward to this quick run of games, the players enjoy it, but it is a very hard, especially for them," Allardyce said.
"We will have to rotate the team because there will be fatigue, there will be injuries to deal with.
"If we come out of this period with a few more points, then we'll reassess our aims for the rest of the season.
"Leicester are a hard team to break down, they work very hard for each other. Despite their run of games without a win, they haven't been turned over by anyone, it's only ever by the odd goal.
"I saw the Leicester game against Manchester City and I thought they did very well. There are a lot of dangers in Nigel's teams that we need to be well aware of. They won't lie down and sit back."
Leicester's 1-0 home defeat to Manchester City last Saturday left them five points adrift of safety and, barring an emphatic win at Upton Park, the Midlands club will be bottom at Christmas, a position which only two teams in Premier League history have managed to stay up from.
A run of 11 games without a win, coupled with Pearson being charged for verbally abusing a fan in the 3-1 loss to Liverpool earlier this month, has placed the Leicester boss under increasing pressure.
Pearson is determined to turn Leicester's fortunes around, but knows that his players will be severely tested by a West Ham side that has been given another dimension by striker Andy Carroll's performances since returning from injury.
"Recently we've lost a lot of tight games. It's now about finding that elusive win," Pearson said.
"West Ham are a side in form and it's always a good atmosphere there. They can mix their game up. We'll have to deal with that."
Striker David Nugent has returned to training for Leicester, who will be without defender Matthew Upson (ankle) and goalkeeper Kasper Schmeichel (foot).