Clarke said: “You cannot say if it is possible or not until somebody does it. We said at the start of the Carling Cup we would take it seriously, and we have done.
“We have had some difficult matches and we are still in it at the semi-final stage. It would be silly to get to the semi-final stage and not think you can win the competition.
“The other three competitions will take care of themselves in their own time. All you can do is approach every match and try to win it.”