BREMEN, Germany - Werder Bremen has signed Switzerland defender Francois Affolter from Young Boys Bern.

The Bundesliga club says Affolter will be on loan until Dec. 31, when Werder can exercise an option to retain him on a full contract.

The 20-year-old defender arrives at a time when two of Werder's central defenders are out. Naldo is not playing because of a knee problem and Sebastian Proedl had surgery to repair a broken cheekbone.