"If I was betting on the outcome of next weekend's semi-final, the score would be 1-0. I just hope it's Liverpool celebrating," said Rush.
"The way recent fixtures have gone involving the clubs, the side who scores first will be confident of going on to win the game.
"It's vital Liverpool get their noses in front. If Chelsea have a weakness, it's when they are asked to come from behind and break down tight defences.
"This is the tactic Rafa Benitez has used most against Jose Mourinho, and I don't see him changing his approach too much before next Saturday.
"They may have their second consecutive title in the bag, but Mourinho will know he's facing a stronger Liverpool team now compared to one which beat him in the Champions League a year ago.
"With every month which has passed, the gap between Liverpool and Chelsea has shortened. For Benitez to reduce the gap by nearly 20 points is a huge achievement, even if it's still not quite enough to make his side Premiership contenders just yet. The FA Cup would be worthy consolation.
"Liverpool will also have another crucial advantage - the benefit of 'home' support. Playing the game at Old Trafford is a major plus for them.
"I know from my own experiences in FA Cup semi-finals that the Liverpool fans will dominate the noise level. Benitez's players will feel they're at home, not at a neutral venue."