Sam Allardyce impressed with Everton under Roberto Martinez

West Ham United boss Sam Allardyce has said that Everton present a different challenge under Roberto Martinez ahead of the Toffees' visit to Upton Park this afternoon.

The Spaniard has implemented a game based on keeping possession since he took over from David Moyes, who left for Manchester United at the end of last season.

Allardyce also believes that the former Wigan Athletic coach has added well to his squad, praising in particular the signings of Gareth Barry and Romelu Lukaku.

"Our job on Saturday is to make sure we know what we're playing against," Allardyce told reporters. "They will try and pass the ball out from the back more than they did under David Moyes but after that they generally play the same as they did under David.

"They've got a very good variety of players added to the ones that were already there. Gareth Barry in particular is an outstanding acquisition from Manchester City and with Romelu Lukaku joining their frontline as well he's given them some excellent options.

"They had a fantastic result against Chelsea last weekend so we're expecting a tough match on Saturday."

The Blues are one of two teams - along with Merseyside rivals Liverpool - still unbeaten in the Premier League.