Liverpool boss Jurgen Klopp says they won't take lightly Villarreal tomorrow night.

The Reds welcome the LaLiga outfit in the first leg of the Champions League semifinal clash at Anfield on Wednesday night with Klopp's side favourites to reach another final.

But Villarreal have proved they are no pushovers by beating Juventus and Bayern Munich to reach this stage of the competition and Klopp has warned that Liverpool will not take them lightly.

"There might have been a slight advantage [for Villarreal] where Juve or Bayern might have underestimated them but that won't happen with us. They want to be part of the final but it's the same importance for us," he said on Tuesday.

"They're seventh in LaLiga. After they won the quarter-final with Bayern, in between they played Bilbao and Unai changed 11 times. Spain is obviously competitive.

"It's a difficult league to be successful in but Unai shows he has a plan for each result 1-0 up, 1-0 down etc.

"We have properly analysed Villarreal. I have proper respect for Unai and them. I watched them properly and wow! Impressive.

"He is a detail-obsessed manager. Different ways to press and react to different results. A world-class coach doing an incredible job."