Liverpool manager Jurgen Klopp has warned that Manchester City will prove to be his side's toughest opponent this season ahead of their meeting at the Etihad this Sunday.

The Reds will leapfrog Pep Guardiola's side in the table if they fail to lose in Manchester, and Klopp has already attempted to play down the significance of the clash in the race for a top-four finish.

The stats are on Liverpool's side, however, as they boast the best head-to-head record of the top six, with five wins and four draws from their nine games so far, but Klopp thinks that facing City is a different kettle of fish.

"I think there were other games we played much better than these games," he admitted in his weekly press conference. "In these [top-six] games we have some ideas, if you want, but it was always really hard work. It was not genius. You have to win all of the decisive challenges, all of them.

"We felt so far good in these games but for me, it's the most difficult team to play - City. The Pep Guardiola style... that's real football. It's difficult to defend against them and a lot of teams have felt it already.

"We know what we have to do there. If we can do it? I don't know in this second, but we will try everything to do the right thing. It could be a fantastic game to watch.

"If we are passive against City, no chance. We need to be active, we need to be brave."

Jordan Henderson and Daniel Sturridge have been ruled out of the clash, while Roberto Firmino and Divock Origi will face late fitness tests.