The Gunners have made a solid start to Unai Emery’s reign despite some defensive issues persisting under Arsene Wenger’s replacement.
Arsenal have conceded 32 times in 23 games in the Premier League this season to highlight their weakness at the back.
Emery signed Torreira in a £26m deal from Sampdoria in the 2018 summer transfer window to improve their midfield options.
The Uruguay international has been a big hit with the Arsenal supporters thanks to his tenacious performances in the middle of the park.
However, former Arsenal star Merson would like to see Emery sign Doucoure to further strengthen his options in midfield.
“Arsenal are now showing their true colours,” Merson told Sky Sports.
“Until they sort out the defence, they won’t be able to achieve anything.
“They should sign Abdoulaye Doucoure at Watford – he’d walk into the team. I’d take him tomorrow morning. He’s a much better player than Torreira and he scores goals.”
Doucoure has scored three goals and has made five assists in 22 games in the Premier League this season.
The French midfielder has been an instrumental member of the Watford team since his move to the London side from Rennes in 2016.
The 26-year-old has scored nine goals in 72 games in the Premier League over the past two and a half seasons.
Arsenal are in fifth place in the Premier League table and three points adrift of Chelsea FC in the race to secure a Champions League qualification spot.
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