Liverpool had a commanding lead in the first leg of the contest last week, winning 2-0 at Anfield.
The Reds are in the Champions League final after a run of form. However, they must complete a task in Castellon.
Villarreal will be confident despite their deficit, having already produced fantastic second-leg displays against Juventus and Bayern Munich this season.
And Liverpool will be aware that they must tread carefully as they attempt to reach the Paris final.
They will be hampered, however, by the absence of forwarding Roberto Firmino, who will remain out, according to Klopp.
In his pre-match press conference, he stated, “Bobby [Firmino] is now running.”
“He will go with us but will not be a member of the squad just yet.”
“However, we hope it will be sooner rather than later.” We also suffered a stomach illness, but everyone is fine now.”
Fortunately for Liverpool, they still have plenty of attacking alternatives, including Mo Salah, Sadio Mane, Luis Diaz, and Diogo Jota.
Villarreal will still have their hands full as they attempt to create trouble at the opposite end of the pitch, where they need to score at least twice.