Liverpool midfielder Emre Can will return to the Reds squad for the Europa League semi-final second leg against Villarreal at Anfield.
The Germany international, 22, has missed the past five matches after injuring an ankle in the quarter-final win over Dortmund.
Liverpool must overturn a 1-0 deficit to reach their first European final in almost a decade.
The Reds, who lost to AC Milan in the 2007 Champions League final, are attempting to win silverware in Jurgen Klopp's first season as manager. Since replacing Brendan Rodgers in early October, the 48-year-old German has named strong line-ups during their Europa League run.
Former Dortmund manager Klopp's side were installed as favourites to win Europe's secondary club competition - which would earn qualification for next season's Champions League - after their thrilling win against his old club.
But Villarreal substitute Adrian Lopez's injury-time winner last week gave the Spanish side a slender advantage in the fight to reach the 18 May final.
"If we play our best then we can go to the final," said Klopp. "These players gave me a lot of positive signs about their qualities.
"We are ready. All we did since October was to be perfectly prepared for a game like this. We are not expecting a guarantee to go to the final. We are expecting everything and see what we get for it."
Villarreal have a fully fit squad to choose from, with defender Eric Bailly and forward Leo Baptistao recovered from injuries.
The winners will face either Spanish holders Sevilla or Ukrainian side Shakhtar Donetsk, who drew 2-2 in their first leg, in the Swiss city of Basel.
"We come here full of hope," said Villarreal manager Marcelino. "We are going to give everything we have got and enjoy ourselves. We feel we have the capabilities to make it through to the final."
Three years after being promoted back to La Liga, Villarreal have reached a European semi-final for the fourth time, but have never made it to a final.
In contrast, Liverpool have won five European Cups and lifted the Uefa Cup three times before it was rebranded as the Europa League.
However, while Liverpool need to win the Europa League to qualify for next season's Champions League, Villarreal are already assured of a place in Europe's top club competition after securing a fourth-place finish in La Liga.
"Liverpool as a club have an extraordinary squad of footballers when you consider Benteke cost the whole turnover as Villarreal as a club," said Marcelino.
"But this group of players needs to be proud of what they have achieved as we are already qualified for the Champions League. This is an occasion to be celebrated."