Coach Pete Carroll announced the move Tuesday and called it a non-displaced fracture that Hill suffered in Sunday's game.
"He was playing great ball. The hopes for him coming back next time around and being a big factor for all the playing time and competing and all that, it's there. He was playing his best game," Carroll said of Hill on Tuesday. "He played really well -- hits, running, tackling, all kinds of good stuff, pressuring. So very, very bright future for him and this will set him back for a while, but it's not something he can't recover from."
On his 710 ESPN Seattle radio show on Monday, Carroll praised the way Hill played and didn't dismiss the possibility of keeping him in the starting lineup for Seattle's wild-card game against the Dallas Cowboys on Saturday, even though Thompson is expected to be back this week.
The statuses of left guard J.R. Sweezy and cornerback Shaquill Griffin remain uncertain. Carroll said Tuesday that Sweezy is moving around well without a limp or a boot on his sprained foot, but he'll be a game-day decision. Griffin sprained his ankle Sunday and will try to practice later in the week, Carroll said.
Akeem King stepped in at left cornerback for Griffin on Sunday and would start in his place if needed against Dallas, Carroll said.
The Seahawks re-signed receiver Malik Turner from their practice squad to fill Hill's roster spot.