Watford are the only Championship side to have kept two clean sheets so far this season – but head coach Valerien Ismael admitted he is looking at strengthening that area further as part of “two or three” positions he is looking at.

Despite the new style of playing out from the back putting extra emphasis on the defenders and goalkeeper Daniel Bachmann, they have yet to concede a league goal – though that hasn’t been without moments of real worry due to some unforced errors.

Ismael said he is happy with how his defenders have performed within the wider group.

“I’m pleased with the attitude from all the players, not just the defence,” he said.

“In the two league games we have conceded chances, and we need to avoid that, and when we are at the other end we need to be more ruthless.

“We need to avoid the mistakes at either end of the pitch.

“But it’s a good sign as we have the chance to make it better. I’ve told the players that this is a normal process, accept mistakes are a part of the game.

“We know we will create chances because of our game, the next bit we have to work on is to be ruthless in the dangerous areas.

“I accept that mistakes will happen and I took the pressure out of the players from day one: I said to them they will make mistakes but they should try always to do the right thing.

“We have assessed the squad and tried to find the better solutions – do we need another defender? I know some players are able to play other positions: Sierralta is playing the No.6 position but is actually a centre back.

“We have other options within the team with players who are able to play two or three positions. That gives us flexibility.

“If nothing happens then we are happy with what we’ve got. But we are aware of our positions in the defensive line, and if it maybe makes sense for us to add some strength.

“The season is a long run and at some point maybe we will need more. It’s always an assessment: the defensive line, the front line. In some positions we are good and we don’t need to think about them.

“But there are two or three positions that are in my mind at the minute.”