Following Seattle's thrilling 27-24 road win over the San Francisco 49ers, Lockett was taken to hospital due to severe swelling caused by a lower leg contusion.
"Well, I think there's a lot of swelling. The contusion caused a lot of swelling right away and they've got stuff," Seahawks head coach Pete Carroll said postgame, according to Nick Shook of NFL.com.
"There's concerns about that. So, we just got to take care of him and we're ahead of it, so we should be in good shape but sorry to see him."
Lockett, 27, was relatively quiet in Monday's victory, hauling in three catches for 26 yards against a stingy 49ers defense.