Chelsea midfielder Jon Obi Mikel is adamant that he and his teammates must be at their best when they take on Manchester City on Sunday.
With a win over Roberto Mancini's side the Blues can close the gap to one point between the sides in the Premier League and effectively end their title hopes.
Mikel told the club's official website: "It will be an important game for both teams. If we can beat them it will enable us to narrow the gap.
"If you look at their side, when they play against teams outside the top four they sometimes struggle a bit, but when they play big games they always turn up."
Chelsea are third in the Premier League but are just two points ahead of Arsenal in fifth place.
