Rucker didn't take part in Wednesday's practice due to a neck injury, Matt Kawahara of the San Francisco Chronicle reports.
Rucker's status was in doubt for Week 5 due to what is likely the same neck issue, but he wound up playing 16 defensive snaps in the contest. It's possible the training staff is holding him out to ensure his health for Week 6, but the final injury report Friday should reveal more about the prospects of him suiting up against the Seahawks.