"There is no dent in our confidence. At the moment we are top and we will continue believing we can go on until the end," said the Swiss defender.
"The Wigan game is a little set-back because we have drawn a few games on the trot but we haven't lost. The confidence is sky high and we are going to continue like that. We will continue to play the way we have been, but in hopefully better conditions.
"Hopefully in front of our own crowd and in better conditions than at Wigan, we can do the job the way we want to. We want three points every game and Middlesbrough is a good opportunity to come back strong and show everybody that we are up there.
"We have to take the positives out of the (Wigan) game. There was good character and good fighting spirit.
"If someone doubts our fighting spirit you saw it - everybody was committed, there was a great attitude on the pitch so to come out of a difficult game with a result after a hard week is definitely positive."