Arsenal have appointed Raul Sanllehi, the former Barcelona director of football, to a new position as head of football relations to complete the club’s biggest off-field overhaul since Arsene Wenger ­became manager 21 years ago.

Sanllehi’s arrival follows that last week from Borussia Dortmund of Sven Mislintat as the head of recruitment and the summer appointments from Team Sky cycling of Huss Fahmy as contract negotiator and Darren Burgess from Australian rules as director of high performance. Former goalkeepers Jens Lehmann and Sal Bibbo were also added to the first-team coaching staff this year, while captain Per Mertesacker has agreed to become the academy manager next season when he retires from playing.

The changes are by far the most wide-ranging since Wenger arrived at the club in 1996 and, although they are certainly part of a plan to strengthen the infrastructure and support around the manager ahead of his eventual departure, the Frenchman has agreed to them.

Wenger signed a new two-year contract in May and, despite the intense and sometimes angry debate among fans about his future, there has been no sign of him losing his enthusiasm for the job.