Redknapp added: "You can win a cup and have a bit of luck on the way but to get to a Champions League position would be done through a whole season. It would be great for us.
"It is a one-off game at Wembley, a great day out for the fans. If you win it everybody enjoys it but Tottenham won it two years ago and then went into freefall. So it didn't do them any good."
Redknapp feels the title will be won by Chelsea or United, leaving Arsenal and Liverpool to scrap with Spurs, Aston Villa and Manchester City for the final two qualifying Champions League spots.
"The four clubs have had a monopoly on it," he said. "I'm not saying we're going to do it but we have got a chance.
"It's not impossible. If we sit here and say we're never going to do it, we never will.
"If the manager doesn't believe it, the players would think 'why should we?' But it is possible. We have a good squad here.
"This time last year, you wouldn't even have considered us breaking in there, we were at the bottom of the league.
"We are getting to the stage where it is possible for us to go away (to top-four clubs) and feel like we've got a chance of winning."
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