Arsenal should complete the transfer of centre-back Sokratis Papastathopoulos from Borussia Dortmund next week, Press Association Sport understands.

The 30-year-old Greece international is expected to put the finishing touches to a deal reported to be worth around 20 million euros (£17.7million).

New Arsenal head coach Unai Emery has already signed Swiss defender Stephan Lichtsteiner from Juventus on a free transfer, while goalkeeper Bernd Leno has joined from Bayer Leverkusen.

Uruguay midfielder Lucas Torreira, away on World Cup duty, is another likely recruit, with a potential £27million deal reported to be being negotiated with Sampdoria.

Arsenal, who finished sixth in the Premier League last season, have also looked to secure some of the current squad on new deals, with midfielder Granit Xhaka and 20-year-old winger Ainsley Maitland-Niles having signed contract extensions.

There have also been recent changes behind the scenes as Emery finalised plans for his backroom staff, with Steve Bould set to continue as one of two assistant coaches but former number one Jens Lehmann leaving his goalkeeper coaching role.

Arsenal have yet to announce the shirt number of German goalkeeper Leno, but his arrival creates uncertainty over the future of veteran Petr Cech and David Ospina. Ospina said he will talk to the club about the situation when he returns from World Cup duty with Colombia.

The club received positive news this week regarding defender Laurent Koscielny, who is recovering following surgery on a ruptured Achilles tendon which ruled him out of contention for France’s World Cup squad.

Koscielny, who captained the side last season under Arsene Wenger, suffered the injury during the Europa League semi-final second-leg defeat by Atletico Madrid on May 3, and is expected to need several months of rehabilitation.

Quel bonheur de pouvoir marcher à nouveau ! 💪🏻 It’s good to walk again 😍

A post shared by Laurent Koscielny (@koscielny_official6) on

In a post on his official Instagram account, accompanied by a short video, a smiling Koscielny, carrying his crutches, said: “It’s good to walk again.”

Arsenal will play Emery’s former club Paris St Germain in Singapore as part of their pre-season schedule next month. The Gunners face Chelsea in Dublin on August 1 ahead of opening the new Premier League campaign at home against champions Manchester City.

Emery made a surprise visit to an Arsenal supporters’ event at the Emirates Stadium on Wednesday night.

The Spaniard hopes to be able to unite the club’s fanbase, which had been divided during the final years of Wenger’s tenure.

“For me, it’s after I met with the staff, now I’m meeting with the supporters. Together, we can make things better and achieve success in the next years,” Emery said on www.Arsenal.com.

“For me, the supporters are like one (part of a) table with four legs. All the legs are very important.

“One leg is the organisation, the second leg is the team and the players, the third is the media who broadcast our success all around the world, and the fourth is the supporters.

“The four legs are very important for the table and likewise for Arsenal. If you lose one leg, you break. I’ve used this metaphor many times to describe our relationship with the supporters.”