The Hornets fell agonisingly short of automatic promotion, going down to a late Leeds winner when a victory would have sent them into the Barclays Premier League at the expense of Hull.
Instead a semi-final meeting with sixth-placed Leicester awaits and Hornets chief Zola said: "It will be tough. They are a team we have already faced twice and we know the quality they have. They know us, we know them. We'll go there and play our game."
He added: "Before the game the players knew the possible scenarios. We will be ready to start again on Monday.
"The players were very tired at the end of the match, they had given everything. It's been tough but we will come back. The expectations have grown this season as we have grown in stature but you have to face that if you want to be a top team."
Zola is hoping goalkeeper Manuel Almunia will shake off the tight hamstring which kept him out of Saturday's match and had such a bearing on the outcome.
Jonathan Bond was drafted in to replace Almunia following the warm-up but his afternoon ended after 22 minutes when he was carried off with a broken nose.
That meant a professional debut for 19-year-old Jack Bonham, but the understandably nervous academy keeper was culpable as goals from Dominic Poleon and Ross McCormack, either side of Almen Abdi's fine curler, sealed Leeds' 2-1 win.
Defender Joel Ekstrand, whose poor clearance gifted Poleon his opener, tried to look at the positives.
He said: "If you had said play-offs at the start of the season we would have taken it. Now we have a second chance to take our place in the Premier League."
- Sports & Recreation
- Manuel Almunia