Victory at Camp Nou last month puts Barca in a good position to reach their fifth final in seven seasons, but Villarreal's away goal gives them a glimmer of hope.
With that in mind, head coach Luis Enrique intends to attack at El Madrigal and take advantage of any gaps caused by Villarreal's need to score.
"With the 3-1 first-leg win, at some point they must come forward," he said. "Our goal is to win the match, and ensure there are no surprises.
"I guess they will be a more offensive version tomorrow.
"Villarreal have a very balanced squad with a great coach. He has resources to make life difficult for any team. We know we need to play well and go win the game.
"We are at an optimum time for results and form, and I hope that this will lead to titles."
Barca lost the final to Real Madrid last season, going down 2-1 at the Mestalla.
