Branislav Ivanovic has dubbed Chelsea's trip to Arsenal on Saturday as their "biggest challenge" so far this season after helping them stay top of the Premier League.
The European champions spluttered to a 1-0 win over Stoke on Saturday to ensure they ended the weekend a point clear of Manchester United at the summit.
Chelsea have enjoyed a near-perfect start to the title race in terms of results, winning four of their five games and keeping four clean sheets.
But they have yet to face any of the current top nine in the league and have not fared well against big teams in other competitions this term.
Full-back Ivanovic insisted it was far too early for Chelsea to be thinking about regaining the title they last won in 2010.
"We have the next game as a very great challenge for us in the Premier League - Arsenal away," he said. "This is the first actual big game for us this season.
"Our performances and quality - we know how it is. But we have to show everyone, and we have to show it every game.
"This is the biggest challenge. I think Arsenal will be a great challenge for us, and we have to really be ready for that."