David Wagner wanted Liam Gibbs ‘speed and ability in tight spaces’ to open up Watford after he replaced striker Adam Idah at a key point in Tuesday’s 3-2 Championship defeat.

That substitution prompted stick from a section of the away support at Vicarage Road towards the German with the game in the balance at 2-2.

Yaser Asprilla pounced in the 77th minute, after George Long parried Wesley Hoedt’s strike, before Wagner introduced Borja Sainz and Marcelino Nunez.

The German explained his logic behind removing Cardiff match winner Idah, and insisted individual errors were the root cause of an eighth league defeat in 12.

“The speed which he (Gibbs) has at the end of the day, and that he is able to have a good back foot turn in tight spaces,” said Wagner. “I think with him and Borja later on, there were exactly moments and movements which we expected from these changes. This is why we why we made this substitution.

“There's nothing about the tactical approach, this is all about focus and concentration and judging the situation in the right manner, and what you can expect from your guys.

"We have not done a mistake like this in the last couple of games, we always looked very solid. But after the first half an hour, it was not the case. Goals change games, everybody knows this, and we gave them away too easy.

“The thing you can do is to finger point, to name it, to show it and to make clear, you have to do better and you are better than this. I'm absolutely not happy. It's not as easy to fix because it's not always the same one.

"Otherwise then it's quite easy that you can say, ‘Okay, come on, you get a break, take a breather, and then you go again.’ But at the end of the day, we have too many of these mistakes, too many big ones, where you can say okay, no one can solve that problem if you do a mistake like this.”

Wagner hailed the previous clean sheet win over QPR as a step forward in addressing one of the division’s worst goals against records.

“The mistakes which we've done, the individual mistakes, which we've done before, and we've spoken about this in the past, we can't do mistakes like this,” he said. “And we've done it again, it cost us and, second half, to be fair, we didn't keep the ball.

"We had so many easy turnovers, so many missed passes, that we were not able to go out of our own half and were caught under a lot of pressure.

"A deserved defeat against a very good side where we made too many mistakes. Disappointing that we did not get something out of the game when we started quite well - first 25, 30 minutes  - and controlled more or less the game and the crowd started to get nervous.”