Sources told ESPN and NBC Sports Northwest that Lockett spent the night at the San Francisco Bay Area medical facility following his team's 27-24 win against the San Francisco 49ers Monday at Levi's Stadium in Santa Clara, Calif.
Lockett was not available for overtime after fielding the final kick of regulation. He had three catches for 26 yards in the win. The Seahawks called the injury a contusion, which is often mistaken for other injuries. Seahawks coach Pete Carroll referred to the injury as a "pretty severe situation."
"Well, I think there's a lot of swelling," Carroll told reporters. "The contusion caused a lot of swelling right away and they've got stuff.
"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. You could tell without having 'No-E' [Lockett] out there we looked different and we need him back."
Carroll also said he didn't think Lockett's injury would last beyond the team's Week 11 bye. Lockett has 793 yards and six touchdowns on 62 receptions in 10 games this season.
The Seahawks return to action with a game against the Philadelphia Eagles at 8:20 p.m. EST Sunday, Nov. 24 at Lincoln Financial Field in Philadelphia.