Aston Villa must handle a “difficult” atmosphere in their “biggest game of the season” as they look to come from behind against Olympiakos, says manager Unai Emery.
Emery admitted his side would have to be much improved to reach the final.
He said: “We must do better. It will be difficult with the atmosphere.”
The former Sevilla and Arsenal boss added: “We need to build a new experience here with our players and our idea. This is the biggest game of the season.”
Villa’s preparations have been hampered by uncertainty over their goalkeeping situation, with Emery unsure if first choice Emi Martinez will be available.
Martinez was suspended for the first leg and was not in the squad for the Premier League defeat against Brighton on Sunday.
Robin Olsen replaced Martinez for both matches, and Emery backed the Swede to deputise again if needed, despite Olsen conceding four in the first leg.
“As a person he is a very respectful man,” Emery said of Olsen. “As a professional he has an amazing career. Being number two to the best goalkeeper in the world is not easy. Always he is positive.
“On Sunday he was fantastic. He could not do anything to save us in the first leg. If he plays, he has our respect.”
Villa are on the verge of qualifying for the Champions League next season through a top-four Premier League finish, and Emery said their season could not be considered any less successful if they fail to reach the Conference League final, where Fiorentina await the winners.
“We have enjoyed getting here,” he said. “To win a trophy in Europe is very difficult. To get here you have to be consistent, but if we don’t win tomorrow, the process is clear.
“Maybe we could be a favourite before the first leg, but they show with us their power and how they want to be a contender and now they are favourite. I will prepare us to come back, but our process does not change.
“In the Premier League, we are having a fantastic season. We have to enjoy both competitions. We have to be proud of our work.”