Xhaka enjoyed an exceptional first season at Sunderland after his move from Bayer Leverkusen 12 months ago, but his former boss in Germany Xabi Alonso now wants to reunite at Stamford Bridge this summer.
The interest emerged earlier today, with strong reports claiming Xhaka has "expressed a desire" to link up with Alonso once again.
Sky Germany even go as far as saying Xhaka and Chelsea "have reached a full verbal agreement" and "personal terms have been fully agreed".
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But Sunderland's stance on their captain is strong and couldn't be clearer.
The Northern Echo understands any offers this summer would not be welcomed and the Black Cats consider Xhaka very much not for sale.
Xhaka still has two years left to run on the three-year contract he signed last summer and Sunderland are under no financial pressure to sell.
Today's links have rocked supporters on Wearside, with Xhaka having led by example on and off the pitch at Sunderland in an outstanding first campaign at the club.
Head coach Regis Le Bris says Xhaka is "like a second coach on the pitch" and the 33-year-old was not just the star man on the pitch last season but of immense importance behind the scenes.
As Sunderland prepare for their second season in the Premier League and a tilt at the Europa League, any uncertainty surrounding the future of Xhaka is the last thing the Black Cats need.
Sky Sports say there has been no contact between the clubs as things stand.
In an interview with Blick earlier this month, Xhaka said: “It’s [Sunderland] a bit like home for me. The city feels like Basel. Like the St. Johann district where I grew up. You can only perform at your best when you feel comfortable in a place.
“For me, the most important thing is that my family is happy. And we are in Sunderland. I’m not even thinking about a transfer. I’m really happy to finally have a summer without any speculation about my future. That’s rarely been the case in recent years. This allows me to fully focus on the World Cup.”
Alonso was head coach of Xhaka at Leverkusen, where the pair won the Bundesliga title together, but the former Liverpool midfielder left last summer and went on to take charge at Real Madrid, though he didn't last long in Spain.
Xhaka was in demand last summer but Sunderland pulled off a remarkable transfer coup in landing the former Arsenal man.
Xhaka is currently away at the World Cup with Switzerland, who have qualified for the knockout stages after winning Group B.