Joe Allen is optimistic Liverpool can overturn their first-leg deficit against Villarreal and reach the Europa League final.

The two teams meet at Anfield for Thursday's semi-final second leg after the Spanish side won the opening encounter 1-0 at El Madrigal thanks to Adrian Lopez's stoppage-time strike. 

The winners of the tie will face either holders Sevilla or Shakhtar Donetsk in the final in Basel on May 18 and midfielder Allen is confident Liverpool will be there.

"Villarreal will have their work cut out," he told UEFA. "On another night we would have won [the first leg], which would have been ideal. 

"But I'm confident that we have got enough to win this second leg and put them out.

"There was an extremely fine line between us imposing our gameplan in the first leg and getting a 1-0 win ourselves, and the way the match actually turned out. 

"As hard as it was to concede that goal, particularly so late, I really thought we all gave a good account of ourselves. Games like that are what you look forward to all career – big matches in a semi-final of a UEFA competition.

"We did our preparation well and we learned a great deal for the game at Anfield. If – and only if – we go through, we'll be able to look back and, despite losing 1-0, say we did a very good job in Spain."

Allen acknowledged Liverpool had found it difficult to cope with the playing style of Villarreal, which he found significantly different to that of Premier League teams.

"It was a tough experience," added the Wales international, 26. 

"The tactical element was a big test for everyone in terms of coming up against a team which plays differently to what we are used to. 

"Technically, they move the ball so well. Top Spanish teams tend to be possession-based – something we don't meet week in, week out in England."