The 30-year old Switzerland international is set to leave Germany to join Swiss outfit FC Zurich in January but Stuttgart general manager Horst Heldt has confirmed that a replacement has already been found.
"We have already found someone for the left full-back position, we are almost through negotiations," he told Deutsches Sportfernsehen.
"We are set to prepare ourselves further and sign new players on one or two different positions this January."
Heldt added that Czech midfielder Jan Simak was also close to leaving the Mercedes-Benz Arena.
"Jan Simak is in talks with different club, we are both wanting to find solutions for him this winter," he added.
"Regarding further players on the verge of our first-team squad, it is too early to say actually."