Senderos sidelined for six months
"The club can confirm Philippe Senderos underwent surgery on his Achilles tendon in Finland today," the Premier League team said on their website on Wednesday.
GEAR: Get a Swiss shirt
"The surgery went well and the club are hopeful of a return to training within six months."
Senderos, who left Arsenal in June, pulled out of Switzerland's squad for Wednesday's friendly against Austria due to a minor toe injury.
He then hurt his Achilles while training with his new club ahead of the opening league match of the season at Bolton Wanderers on Saturday.
"It's incredibly bad luck for Philippe. A hard blow to him personally, for his club but also for the national team," coach Ottmar Hitzfeld told the Swiss FA's website.
The Swiss FA said Senderos had surgery at the same clinic that treated David Beckham earlier this year after the former England captain suffered a similar injury.
Senderos was in Switzerland's World Cup squad but managed just 36 minutes of action after injuring his ankle in a surprise victory over Spain in their opening game.