Silvestre signs for Werder Bremen
Werder are in this season's Champions League, drawn in a group with defending champions Inter Milan, one of Silvestre's former clubs, Tottenham Hotspur and Twente Enschede.
The 33-year-old Silvestre, who spent nine seasons at Manchester United before joining Arsenal in 2008, was without a club after his contract with Arsenal ran out in June.
"A new and big adventure starts for me today in Bremen," the 33-year-old said. "There were other offers but I was fascinated by (coach) Thomas Schaaf and (director) Klaus Allofs."
Bremen also said striker Claudio Pizarro pulled a thigh muscle during their 4-2 win over Cologne on Saturday and would miss Peru's internationals against Jamaica and Canada next week.
He could return for Werder's next match against champions Bayern Munich on September 11.