Rice suffered his second concussion of the season in last Sunday's 23-17 loss to the Redskins, prompting his move to the IR. He was also concussed in a Week 10 win over the Ravens.
The former Pro Bowl wideout has 32 receptions for 484 yards and two touchdowns in nine games this season. He signed a five-year deal with the Seahawks during the offseason after spending the first four years of his career with the Vikings.
Seattle (4-7) hosts the Eagles Thursday night.