According to a report on the San Jose Mercury-News Web site on Friday, the contact is for two years and $6 million.
Bruce was released last week by St. Louis, where he was the franchise's all-time leading receiver.
Bruce has spent all 14 of his NFL seasons with the Rams. He has 14,109 yards and 84 touchdowns on 942 career catches. The four-time Pro Bowl player was selected in the third round of the 1994 draft and accumulated the third-most receiving yards in NFL history.