The Sunderland midfielder admitted obtaining false paperwork in 2022, when Covid certificates were required for access to certain activities, venues and international travel in Switzerland. The country's measures were in place until spring that year, with certificates later continuing to be used mainly for overseas travel.
Swiss prosecutors are investigating whether criminal wrongdoing took place. Xhaka is expected to be questioned in Switzerland at the start of October and could face legal consequences, although any punishment has yet to be determined.
The 33-year-old acknowledged his actions in a statement, saying he had been deeply unsettled by the vaccine and had developed a strong mistrust of it at the time.
"Today, I clearly see that this was the wrong course of action. It was a mistake. I am sorry," Xhaka said. "I accept responsibility for this decision, am facing the process of addressing the situation, and am cooperating fully with the relevant authorities."
The Swiss Football Association said Xhaka and team management had jointly agreed that he should miss the upcoming international camp. Switzerland are due to face North Macedonia and Scotland later this month before meetings with Slovenia and North Macedonia in October.
"Once this international break concludes, we will reassess the situation with Granit and discuss the next steps," SFV president Peter Knabel said.
Xhaka, who has a record 152 international caps and captains his country, was recently involved in Switzerland's World Cup campaign. He has also made six appearances for Sunderland this season, including Sunday's 5-3 defeat by Manchester City.
Sunderland manager Regis Le Bris declined to discuss the matter after that match.
"It is not my area to speak about those problems or situations," Le Bris said. "My area is football. About football, he is really good."
The case follows an investigation into a Swiss doctor accused of producing fraudulent vaccination certificates for people who had not received the Covid-19 vaccine.
There is precedent for criminal penalties in Switzerland. Former national ice hockey coach Patrick Fischer was fined 38,000 Swiss francs in 2023 after being found guilty of using a fake Covid certificate to work at the Beijing Winter Olympics.
Xhaka has said he will cooperate fully with the authorities as the investigation continues.
