The Blues head to the DW Stadium off the back of three consecutive victories - the most impressive of which came at Stamford Bridge on Monday, as Andre Villas-Boas' side became the first domestic team this season to take three points off of City.
However, Cech has warned his Chelsea teammates that failure to beat lowly Wigan this afternoon will undo all of their recent hard work.
"Beating City was important of course because it enabled us to get a bit closer," he explained. "City are seven points in front so they still have an advantage.
"But suddenly the pressure from the teams below is a bit bigger so let's see how they cope with it.
"We can only take advantage of any result if we win our own game, Monday's win will count for nothing unless we beat Wigan."
The Latics have struggled to find any kind of form all season long, and with only three wins to their name in the 2011-12 campaign, Chelsea will be regarded as the overwhelming favourites, but Cech knows it will still be a tough test of the club's title credentials.
"For them any point will be a great result because we are the favourites for the game," he continued. "They will try to get whatever they can but it's really up to us.
"If are attitude is right we should get the three points, and with City playing Arsenal this weekend, two teams who are around us, let's see what happens."