"All I'll say is that it's not over until the fat lady sings," he told the club's official website.
"It's not finished until the whole tie is done.
"We are recognised as being very good at home, and if we play the way we usually do, we will make enough chances to win 2-0.
"It's a matter of taking those chances on the night. We have to put them on the back foot straight away.
"Anything is possible. If we go out there and play the way we know we can on Thursday, it will be difficult for Hamburg.
"Everyone is confident, we've spoken about it already and we have got the belief that we need.
"It would be a dream for me to win the UEFA Cup after starting at the club as a kid - achieving things and being successful here was part of the reason I came back."