The Merseysiders knocked Italian giants Roma out of the Uefa Cup on Thursday 2-1 on aggregate and must now refocus on beating Division One side Birmingham at the Millennium Stadium.
Rush holds the player record for most League Cup wins.
He believes his former club are now poised to lift the trophy again for the first time since 1995. I think that the most important part about the Worthington Cup is that it gets you into Europe. That's a big incentive for clubs now because it's a way of getting into Europe quite early on. If you've qualified for Europe by the end of February it gives you a chance to maybe concentrate on getting into the Champions League. Obviously being in Cardiff there's a lot of people who have never even seen the Millennium Stadium.