Roberto Mancini has told his Manchester City players they need to display "200%" commitment to win the FA Cup.
City face Wigan at Wembley on Saturday with Mancini convinced that the underdogs will be particularly dangerous because they might not get this chance again.
"For them it is the best moment in their life," the Italian said. "If you play against team who plays for relegation and if you want to win, you should play not at 100% but 200%. If you don't play well, if you don't play a good game, you can't win."
Mancini expects Wigan to give City a difficult game. The 2011 FA Cup winners have prevailed in both league meetings this season, 2-0 and 1-0, but neither has been a straightforward win.
The City manager added: "Every game we play against Wigan we had a problem. We never win easily. First of all, because they try to play football always. When they are losing a game, they continue to play football because they want to attack with a lot of players and when they attack they are very dangerous."
Mancini has tipped his opposite number, Wigan's Roberto Martinez, to manage a bigger club and hopes that Athletic and Sunderland survive in the relegation battle.
He said: "I hope that Sunderland [stay up] because [Paolo] Di Canio is manager and Wigan because I like the chairman [Dave Whelan] and Roberto Martinez. I think Martinez can deserve to manage a top team."
Mancini said his abiding memory of his rivalry with Sir Alex Ferguson was inflicting the Scot's heaviest defeat in his 26 years in charge of Manchester United.
He added: "You think about the derby when we won 6-1 at Old Trafford. I think that it is impossible. I don't think there is another tie like this."