SANTA CLARA -- Running back Marshawn Lynch averaged 4.3 yards a carry during his two seasons with the Raiders before playing his final game in mid-October of last year due to a core muscle injury.

His career was presumed over until this week.

The Seattle Seahawks on Monday signed Lynch, 33, due to a rash of injuries. Lynch will make his comeback on Sunday night against the 49ers in a game that will determine the NFC West champion.

The 49ers are expecting the same Lynch, who earn selections to five Pro Bowls and has more than 10,000 rushing yards in his career.

The 49ers spent some time on Tuesday watching film of Lynch.

“Sometimes you just don’t lose those characteristics and those traits,” 49ers defensive tackle Sheldon Day said. “So we’re definitely preparing for Beast Mode.”

Pete Carroll’s team lost running backs Chris Carson (hip) and C.J. Prosise (forearm) to season-ending injuries on Sunday in a 27-13 loss to the Arizona Cardinals. Earlier this month, running back Rashaad Penny sustained a season-ending ACL injury.

“I saw the backs they lost, so you knew they were going to sign someone,” 49ers coach Kyle Shanahan said on Tuesday. “And they signed a good one.

“I know Marshawn will come in, and he’ll be ready, regardless of how much time he’s had off. Marshawn is a competitor. He’s a battler. So it was smart of them.”

 

Rookie Travis Homer has been with the organization all season, but he has just eight rushing attempts for 52 yards this season. The Seahawks are likely to mix in Lynch and Turbin, who also has not played this season.

Shanahan is not sure exactly what to expect, but he does not believe the Seahawks will settle one just one running back to carry the load.

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“It depends on how much those guys have been working out and stuff like that,” Shanahan said. “I think it is a little different with the running back position. There’s a lot that goes in with people learning the scheme and game plan and everything, but you can use a running back a lot easier.

“The rest will (depend on) how much they’ve worked out, which will keep them in shape. Obviously, no one’s in football shape, but I don’t think they’re planning on any single guy carrying the load the whole game.”