Tevez scored twice in City’s 4-2 victory at Stamford Bridge.
“We’ve been playing very well and we’ve had some great results against the top sides,” Tevez told the club’s official website.
“But with the so-called weaker teams we have not done so well, not necessarily because we have not played so well, but because the result has not gone our way.
“The thing now is for us to make sure we keep calling on the spirit that we showed at Chelsea and continue to play the way we are doing.
“We must show that same character and personality so that we can win the game at Sunderland and keep up our challenge for fourth place.”
“Obviously it’s important that I score goals, but I think it is more important for the group that the team plays well and continues to play well,” added Tevez.
“As for working hard, if I don’t score then I have to run after the ball and try to win it from the opposition. So that’s a part of my game I have to concentrate on and try to do well.”