Chelsea midfielder Juan Mata knows they face a massive test against Manchester City this weekend.

The 23-year-old, who has been a revelation since his £23.5million summer move from Valencia, is under no illusions how hard it will be to stop a team that won 6-1 at Old Trafford in October and have dropped just four points all season.

"Man City are having a great Premier League," he said. "They are the leaders, they win in every game and we hope that here at Stamford Bridge they will have a difficult game.

"We lost against Liverpool, against Arsenal, against Manchester United, but we hope that against Manchester City we'll change this."