The two teams meet at Elland Road on Saturday afternoon (K.O. 2.30pm) as part of a triple-header of games.
Knowles states his side are not thinking about their victory over the Warriors in the Good Friday Derby.
He said: “I can’t wait, it’s a big game against Wigan, with it being a derby game, as well as it being a semi-final at a great stadium. It doesn’t really get much bigger for both sets of fans and players, it’s massive.
“I don’t think there are any sort of underdogs or favourites in this game because it’s all on the line. The two teams will really go at it, and with the atmosphere it will be nip and tuck.
“The Good Friday Derby doesn’t come into it. Wigan are the form team at the minute, they’ve been really dangerous, while we’ve got a couple of injuries and things we need to deal with.
“We’ve been keeping a close eye on them, seeing how they have been going. We will have to deal with their threats. I don’t think I could catch up with Jai Field or Bevan French if they made a break, there’s no chance of me chasing them.”
Despite coming from Cumbria, Knowles says he already knew a lot about the rivalry between the two teams.
“It’s something that’s not really said but you just know about it,” he added.
“There’s a good hatred between the sides, where both teams have respect for each other but want to get the win against them more than anyone else.
“You realise how much it means to both towns when you see the fans are walking around. You could be in the supermarket and you’ve got people grabbing hold of you and sharing their thoughts.
“Growing up in Cumbria there are no Super League sides, but you walk around people have either a Wigan shirt or a Saints one, so you know what it is all about and how huge the rivalry is.