The Blues' under-fire boss Andre Villas-Boas has admitted that their Champions League clash against Valencia this week is 'a life-and-death game'.
Mata said: "One result can change everything - that's football.
"The most important thing when in a group of people is that in your worst moment you stick together. I am sure we can change the situation."
Ahead of facing his old Spanish club, he said: "The important thing is to keep creating these scoring chances - and playing our style of football. It's our philosophy and the manager's philosophy. Maybe we have to improve our finishing."