Marcelino warned “Real Madrid are likely to put seven past us” if Villarreal did not tighten up defensively after Thursday’s 3-3 draw with Viktoria Plzen.
The Yellow Submarine were forced to settle for second place in their Europa League group after they conceded three goals in the Czech Republic and needed a last-gasp Bruno Soriano equaliser to avoid a fourth straight away defeat.
“I worry about our defensive balance as scoring as many goals as possible to win games isn’t sustainable,” he said after the game.
“We must improve our defensive intensity because it’s not at its maximum. If we defend like we did [on Thursday] against Real Madrid, they’re likely to put seven past us.
“We must look to greatly improve in this aspect, we’ll work hard and see if we can change it.
“[On finishing second], we have to swallow the situation, although it’ll be difficult because there are tough opponents awaiting us. We’ll see how we are when the draw is made.
“I’m wondering what happened for us to come here and play like we did in the first half.
“What worried me most was our attitude in the first half as the team were never at the level we demanded of ourselves.
“We weren’t intense when we didn’t have the ball, and when we did we didn’t know when to attack or counterattack.
“We gave a little more in the second half and were able to overcome the 1-2, but we failed to maintain our momentum when it was time to kill off the game.”