Before their 3-2 defeat in chilly St Petersburg, the Lisbon club were five points clear of Porto at the top of the Portuguese Premier League and full of confidence. Now, they are second in the league, trail Porto by three points and long for a win to knock out Zenit.
Since Roman Shirokov's last-gasp goal gave the Russian Champions the upper hand, Benfica have failed to win all their league matches, recording one draw and two losses. The most devastating defeat was at home to arch rivals Porto last Friday.
Benfica lost the Classico 3-2, let down by an unusually fragile back four and by goalkeeper Artur who, highly praised for his steady performances this season, was caught in no-man's land as Porto scored the 87th-minute winner.
"We must move on because we are in a reasonable situation to eliminate Zenit. Let's see if the team can recover from the defeat because the players feel this one was undeserved," Benfica coach Jorge Jesus told Portuguese television.
"The return of trust requires victories. In the last four matches we drew one and lost three so we go into this Champions League match in a situation which is not easy, but this is our life."
An added concern for Jesus is the likely absence of Argentine centre-back Ezequiel Garay due to a knee injury.
Still, the Eagles will take encouragement from the performance of striker Oscar Cardozo, the club's top scorer in the league and Champions League.
Despite his unstylish approach to the game, the no-nonsense, lanky Paraguayan scored a brace against Porto and applied his famous left foot and sharp sense of opportunity to good effect.
MALAFEYEV BACK
Zenit have welcomed back influential goalkeeper Vyacheslav Malafeyev, who has fully recovered from a calf injury, and defender Domenico Criscito, who missed the first leg in St Petersburg because of food poisoning.
Both the experienced Malafeyev, who turned 33 on Sunday, and Italy international Criscito played in Saturday's top-of-the-table Russian league match against second-placed CSKA Moscow, which ended in a 2-2 draw to maintain Zenit's six-point lead over their rivals.
Zenit coach Luciano Spalletti has lashed out at CSKA for turning down his request to play their match a day earlier so that Zenit could better prepare for Tuesday's clash with Benfica.
"Two years ago CSKA were in a similar situation and we had no problem with playing our match earlier because we all felt like being Russians and wanted to help a Russian club to do well in European competition," Spalletti told local media.
"Now certain people feel like they are less Russians than we were then," the Italian added. "I just don't understand that."
Zenit's Portugal midfielder Danny is out after having surgery to repair torn knee ligaments last month, while forward Andrei Arshavin, who was loaned by Arsenal last month, is ineligible for the Champions League having played for the London club in the competition earlier in the season.
Teams (probable):
