Andoni Iraola has cited Ronald Araújo as a key factor in Liverpool’s improvement at set pieces but admitted Arsenal pose the “biggest challenge” to his team’s defensive record on Sunday.

Liverpool have not conceded a set-piece goal in the Premier League and have shipped only one overall, Conor Gallagher’s consolation header past Giorgi Mamardashvili in Tottenham’s Carabao Cup defeat at Anfield in September. Liverpool’s resilience stands in stark contrast to last season when Arne Slot’s side conceded 20 non-penalty set-piece goals in the Premier League. That was the joint-most in the competition alongside Crystal Palace and Iraola’s Bournemouth.

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The Liverpool head coach credits his assistants, Tommy Elphick and Shaun Cooper, and the club analysts with this season’s set-piece figures, and says the addition of Araújo to his defence has played a major role.

“It definitely helps having a centre-back at right-back when we talk about defending set pieces,” said Iraola, who could have Dominik Szoboszlai and Víctor Muñoz back from injury. “It helps with the height and the physicality of the team.

“It helps us to defend better but it is true that you also lose a little bit offensively on the other side. Offensively we cannot demand of Ronald the same thing as other full-backs and what they give us, but we have to balance this with other patterns.”

Arsenal scored 25 set-piece goals, excluding penalties, en route to winning the title last season but have yet to show the same prowess.

“It is very early in the season and they hadn’t scored [from set pieces] until last weekend and now they have scored,” Iraola said. “I hope they stay that way for a while but they are a big threat.

“From set pieces they are a big threat. They have very tall players who are very good headers and they work it very well. They give you a big demand and I think we will have to defend very well. I think we have, touch wood, dealt very well with defending set pieces so far this season. But Arsenal is probably the biggest challenge.”