Chelsea boss Jose Mourinho believes West Ham’s new signings and the return of key players from injury mean they could pose a bigger threat than the Premier League table suggests.
Sam Allardyce’s side are in the bottom three and enduring a difficult season so far.
But their injury problems seem to be easing and they have been boosted by the signings of striker Marco Borriello and midfielder Antonio Nocerino.
“West Ham are in trouble in the table but I look at them and I feel a difficult match,” Mourinho warned.
“They have new players and they have had time to work and rest from the difficult Christmas period they had, especially because they had so many injured players.”
But the Hammers will be underdogs at Stamford Bridge, where Chelsea will be looking to continue their recent good form.
The third-placed Blues have won seven matches in a row in all competitions and are only two points behind leaders Arsenal.
Mourinho said: “We are playing well. The last game against Stoke was a 1-0 but a good 1-0.
“You never know what is going to happen in the next match, but the results are arriving as a consequence of the team playing very good football.”