Southampton manager Ronald Koeman has claimed that Chelsea are capable of 'punishing' his team if they are not on their best form in Saturday's Premier League match at Stamford Bridge.

Jose Mourinho's side have had a torrid start to the season, having picked up just eight points from a possible 21 in the top flight.

Southampton have just one more point than their opponents, but head into this weekend's match on the back of a 3-1 victory over Swansea City.

Ahead of the Saints' visit to West London, Koeman has insisted that his players need to step it up if they are to come away with points.

"We have to play on a higher level than last weekend because Chelsea will punish you," Koeman said in today's press conference. "They have a fast transition and you have to play good counter-attacking football. In all aspects we have to do it better than last week.

"Maybe defensively they have lost a bit but still they are very strong and they have the quality and the players to give a good reaction."

In this fixture last season, both sides gained a point in a 1-1 draw.