Arsenal manager Arsene Wenger has admitted that his side have a "big challenge" on their hands when they face West Ham United this weekend.
The Gunners make the short trip to Upton Park on Saturday to take on a team who are two points ahead of them in the Premier League table.
"West Ham have a good balance, they are efficient, they are a good mixture I must say between direct play and playing on the ground," said Wenger.
"Technically they are quite sound in midfield, they have [Andy] Carroll and [Carlton] Cole up front who can go for high balls.
"We know we will have a big challenge there, we know we will only get away with the points if we perform at our best."
Arsenal go into the match having not lost to the Hammers since April 2007.