The Gunners could also be set to welcome another summer arrival as they continue their efforts to sign Ajax defender Jurrien Timber.
After finishing as runners-up last season, Arsenal are making preparations for another Premier League title charge.
Pablo Mari and Ainsley Maitland-Niles have been their only departures thus far, but Xhaka could be the next star to leave.
The 31-year-old is closing in on a move to Leverkusen, who finished 6th in the Bundesliga.
With the Swiss international now in the final year of his contract, Arsenal have decided to cash in on him this summer.
He will leave north London after seven seasons at the club in which he scored 23 goals in 297 appearances across all competitions.
Although more outgoings could follow, Mikel Arteta's side are also working on incomings ahead of the new campaign.
Arsenal are confident of completing a £40million deal for Ajax star Timber, who is set to undergo a medical at the club.
He will be one of the latest new names to join, with Kai Havertz being their first of the summer and Declan Rice likely to be next.
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Timber will arrive as part of the Gunners' already impressive defence, one that will be bolstered by keeping hold of one of their top stars.
William Saliba's new deal is set to be announced this week, with a fresh contract for winger Reiss Nelson also close to being made official.
Arsenal are likely to remain active in the summer as they look to go one step further under Arteta next season.
Champions Manchester City have strengthened with the signing of Mateo Kovacic, while Josko Gvardiol is also linked with a move.