Watford head coach Javi Gracia has labelled Unai Emery as one of the best coaches in the world and urged his side to be switched on at set-pieces against the Gunners.

Emery was appointed as Arsene Wenger’s successor in the summer when the long-serving Frenchman decided to step down at the end of last season and after a tough start to the campaign, the North London side are currently in a rich vein of form.

The Gunners have won their last six games in a row in all competitions and are currently in sixth place in the Premier League.

Watford, meanwhile, sit two places above the North London side and the Hornets have fond memories of playing at the Emirates, having beaten Arsenal on their own turf under Quique Sanchez Flores in the FA Cup and almost a year later in the Premier League when Walter Mazzarri was in charge.

Gracia is friends with Emery, after the duo were team mates together at Real Sociedad, although the Watford boss has yet to taste victory against his Spanish counterpart when the duo have faced each other in La Liga.

The Hornets’ head coach will be hoping that changes this week and he drew comparisons between Emery’s Arsenal and Sevilla sides when speaking to the press earlier this afternoon.

Gracia said: “It’s different because some players are different. I can see Emery’s style in this Arsenal side as he showed in Sevilla and other teams he had trained before. They are a good team because they have good players and they are improving game by game and getting better results. They are in a good moment and we know it will be a tough game for us.

“They keep many characteristics they had before. There are the same players like Bellerin, Monreal and players they have had in the past. Now they have adjusted only the positions of Lacazette, Aubameyang and they are organised in midfield with Guendouzi, Torreira and Xhaka.

"They have adjusted the position of these players, but the style is similar than other years. Always you have to pay attention at set pieces because Emery’s teams always work that situation very well. We need to pay attention.”

Asked about Emery, he added: “I think for me, he is a very good coach and he showed that in all the teams he has been at before coming here. I’m sure he will do a very good job at Arsenal because in my opinion, he is one of the best coaches.”