Frank Lampard insists Derby must not lose belief as they prepare for what he has called their "biggest test" of the season.
The Rams travel to Elland Road on Wednesday night looking to overturn a one-goal deficit in their Championship play-off semi-final tie.
To keep alive their hopes of promotion, Lampard's side must do what they have failed to do on three previous attempts so far this campaign - beat Leeds.
Marcelo Bielsa's side did the league double over Derby - winning 4-1 and 2-0 during the regular season - before a 1-0 success in the first leg on Saturday.
Lampard said: "If we work hard and play as we have done over these past weeks, we've still got a chance.
"We just have to worry about ourselves. We don't have to go crazy. We've come back well from losing situations in games this season. This will be our biggest test yet on that front. We have to believe until the very last minute.
"It's a strong atmosphere. It's a stadium of history. It will be tough but the players need to rise to that. There's pressure for us but there's also pressure for them."
"All I see is a 1-0 game that needs to be turned around. Can we get to Wembley?"
Derby are hoping that Martyn Waghorn will be fit. The 13-goal striker missed the first leg with an Achilles injury but he has been training since.
Lampard said: "Martyn Waghorn is in a similar situation to last week. He broke down on Friday but he is desperate to be involved and is training as we speak.
"So he will be assessed up until the last moment to try to get him involved. He was playing very well for us, giving us everything as a striker - hold-up play, desire, trying to win the ball back high up the pitch, scoring goals, talent - the reason I brought him to the club.
"He's a big miss for us so we hope he can be back and be involved, because he has a lot to offer."
Duane Holmes will be fit, having only recently returned from a thigh problem. The midfielder was substituted after 70 minutes of the 1-0 defeat on Saturday.
Left-back Ashley Cole could also be involved after he resumed training following an absence with a groin injury.