Horton (groin/shin) was a non-participant at Thursday's practice, John Boyle of the Seahawks' official site reports.
After Horton was limited at Wednesday's walkthrough, his lack of activity one day later doesn't bode well just three days before Sunday's road showdown with the Rams. On a positive note, the other Seahawks wide receivers -- Jaxon Smith-Njigba (rest), Cooper Kupp (hamstring/wrist), Jake Bobo (calf) and Cody White (abdomen) -- included on Thursday's injury report all practiced fully. Horton's groin and shin injuries are threatening to sideline him for a second straight game, and Seattle may provide a ruling on his Week 11 availability as soon as Friday.