Rees Odhiambo thought to have bruised heart; Chris Carson has broken leg

Seattle Seahawks left tackle Rees Odhiambo remains in the hospital Monday morning with what doctors believe is a cardiac contusion, or a bruised heart, a source tells ESPN's Adam Schefter.

The source told Schefter that Odhiambo is still meeting with cardiologists to determine the exact injury and how long he'll be out. If his heart is bleeding, he could miss a month or more. If it's merely bruised, he could be sidelined for as little as a week. The injury that Odhiambo suffered is found most often in people involved in car accidents.

Meanwhile, the Seahawks have placed running back Chris Carson on injured reserve. The move was expected after coach Pete Carroll said in his Monday morning radio show on 710 ESPN Seattle that Carson broke his leg in the team's 46-18 win over the Indianapolis Colts Sunday night.

The Seahawks filled Carson's spot on the roster by signing defensive tackle Quinton Jefferson off the Los Angeles Rams' practice squad. Jefferson was a fifth-round pick by Seattle in 2016 and was released when the team trimmed its roster to 53 before the start of this season.

Odhiambo was injured in the third quarter Sunday night when he took a hit to the chest on an interception return. Carroll said after the game that Odhiambo initially got the wind knocked out of him and had trouble breathing while playing the remainder of the game. The issue worsened afterward, according to Carroll, and Odhiambo had to be taken out of the locker room on a stretcher. Carroll said Sunday night that "all of his signs are really stable" and that Odhiambo would remain in the hospital overnight as a precaution.

Odhiambo, a second-year player from Boise State, took over as Seattle's starting left tackle when George Fant tore his ACL in the preseason. If he misses time, Matt Tobin and Isaiah Battle -- who were both acquired in trades before the start of the season -- would be Seattle's in-house replacement options.

Carson was taken off the field on a cart and with an air cast on his left leg in the fourth quarter after it was pinned underneath a defender, causing it to bend awkwardly. Carroll said the fracture is just below Carson's knee, which was not where the team initially feared he may have been injured.

Carroll hinted postgame Sunday and again in his radio show that Thomas Rawls will be Seattle's lead running back in Carson's absence. Eddie Lacy, C.J. Prosise and J.D. McKissic are the other running backs on the Seahawks' roster.

Also in his 710 ESPN Seattle interview, Carroll shed some light on the neck injury that forced defensive end Cliff Avril to leave the game for good in the first quarter. Avril got kicked in the chin while tackling Colts quarterback Jacoby Brissett from behind.

"It caused him a little bit of a loss of control for a second in his hands, and he came back fine and felt OK, but something happened there, so we're going to really be careful here and make sure that we know exactly what's going on and take our time," Carroll said. "It'll take us a while to figure this out."

Cornerback Jeremy Lane was also knocked out of Sunday night's game in the first quarter. Carroll told 710 ESPN Seattle that Lane has a strained groin.