Chelsea midfielder Frank Lampard has admitted playing against Steven Gerrard is the toughest test in football.

The duo line up against each other on Sunday as Liverpool travel to Stamford Bridge to take on the Blues in the Barclays Premier League, and Lampard said games against the Reds always provide a difficult challenge.

Chelsea and Liverpool have had a number of memorable matches in recent seasons and Lampard is looking forward to testing himself against his England team-mate in the latest clash between the two clubs.

"I would say he is the hardest player to play against in midfield because he's got everything," said Lampard.

"He is a very complete midfield player. He's the stand-out one in England. Maybe when we play Arsenal and they are sometimes on top form, you could pick one of their players but Gerrard is the main one for me.

"It's a good rivalry because we get on well and I enjoy playing on the same side for England.

"Stevie is one of the best players in the England team and probably in the world to be honest, so it's always nice to play with great players and against them as well."

Liverpool ended Chelsea's 86-match unbeaten run at home the last time they travelled to the Bridge in the league, and Lampard is wary of the threat posed by Rafa Benitez's team.

"If you asked me who our toughest opponents in Europe have been I'd have to go for Barcelona because they are such a talented team and we have played them so many times over the last few years," he added.

"But in England I would say Liverpool are our toughest rivals for sure.

"Liverpool have a very difficult way of playing against you. They make it hard for you to play, their defence is very strong and they have a lot of players who press you, even up front."

The views expressed in this story do not necessarily reflect the views of Liverpool Football Club.