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 (£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.
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.