Liverpool have struggled for league form in 2012 but have already picked up a trophy after winning the League Cup on penalties against Cardiff.
McAllister won the FA Cup with Liverpool in 2001, and believes that if they are to win at Wembley again their talismanic players need to perform.
“I think the influence that Steven Gerrard has on the game is always big for Liverpool,” McAllister told Yahoo!.
“Generally, when he plays well and is influential then Liverpool win.
“Luis Suarez is very exciting. He is a player who can frustrate at times, as he can give the ball away too easily, but then at other times he is sublime.
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“When it's a cup-tie football and it's tight, you just need someone with that little bit of inspiration and magic, and he can produce that.
“Defensively I don't think Liverpool have had much of a problem this season. Their goals against is as good as anybody in the league. But they have had a problem scoring goals.”
The former Scotland captain believes, however, that some Chelsea players may see it as their last chance to lift the trophy and they will prove very tricky opponents.
“I don't want to be disrespectful to Didier Drogba, Frank Lampard and John Terry, but they are not getting any younger,” he added.
“Each time they get to a final, they will appreciate that it could be their last chance to win a medal.”
The 47-year-old has also been keeping tabs on another of his former clubs, Aston Villa, as they struggle to stay in the Premier League.
“It's been quite alarming watching it,” he said. “Your eye is always taken to your former club, where you have played or worked.
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“This season they lost two key players in Ashley Young and Downing. I think there was maybe a change of tack from the owners as well as far as the money that had been spent there in the past compared to what is being spent there now.
“It's been tough. There have been injuries to key players at crucial times, so they have had to blood some young players that maybe would not have played the amount of games they have had to play. I think they will just have enough to stay up, which is great.”
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