RENTON, Wash. -- Moments after Seattle Seahawks defensive coordinator Ken Norton Jr. spoke with reporters at Seahawks headquarters Tuesday, Marshawn Lynch made an unscheduled visit to the podium and waited for the first question.

Asked what brought him back to Seattle, Lynch shared a brief message, smiled and walked away.

"Happy holidays," he said. "Merry New Year. Y'all have a great day. It's a great feeling to be back. Thank you."

Lynch is still a man of few words. The Seahawks hope he's still a productive runner at 33 years old and more than a year removed from his most recent NFL game. They need him to be after losing starter Chris Carson and backup C.J. Prosise to season-ending injuries last weekend, a massive blow as they head into their regular-season finale Sunday against the San Francisco 49ers that will decide the NFC West champion.

The Seahawks on Tuesday announced the returns of Lynch and another one of their former running backs, Robert Turbin.

"He's an extraordinary person," coach Pete Carroll said of Lynch, who spent parts of six seasons (2010-15) with the Seahawks before the first of his two retirements. "He's just been through so much and we know him as well as I think you could know a guy, and what he brings and what he offers and all. He brings a lot to the table. He's as physical of a player as I've ever been around, as great of a competitor as I've ever been around. So when you get to add somebody like that to your team, it only helps and enhances kind of the mentality that we already cherish."

The Seahawks had been keeping tabs on Lynch for months, as teams do in order to prepare for emergency situations. The possibility of a Lynch-Seahawks reunion began heating up when Seattle lost Carson's backup, Rashaad Penny, to an ACL tear in Week 14. It became a reality after Carson suffered a hip fracture and Prosise a broken arm in last weekend's loss to Arizona.

Lynch went through a workout and took a physical before signing his deal Monday. The Seahawks practiced Tuesday so they can take Christmas Day off and thus weren't required to release a practice report detailing player participation, but Lynch was on the field during the period open to media, wearing his usual No. 24 with the hood of his sweatshirt pulled over his head.

The team's online roster lists him at 215 pounds, which was his listed weight during his final season in Seattle.

"We'll find out how he can play and how he does," Carroll said. "It's been a little while off. He looks great in [our] first couple of looks at him as far as his conditioning and all that. His weight's down and he's in a really good spot for coming and going for it. He was very serious about getting ready for this opportunity. The stroke of misfortune in some regards really opens up the door, which happens at times. He's ready to take the full opportunity at hand and see what he can do to help us."

Asked what's realistic to expect from Lynch and Turbin, Carroll gave a strong hint that neither will be asked to carry the load. He said the Seahawks will "lean on" rookie sixth-round pick Travis Homer, who was their No. 4 option before Penny went down and their only healthy tailback by the end of last weekend's game. He gained 16 yards on five attempts against Arizona.

"I hope that they can contribute," Carroll said. "Travis is ready to go. He's knows everything. He's been through all of our system for the whole year. He showed that he was ready to play football and he did a good job in the game. We lean on him because of his background with us and his toughness and his speed and his playmaking. We're pleased to have that opportunity. That's good fortune to have him ready to go. And then we'll just fit the guys in. Give me a couple days here. This is like the first day."

Lynch won Super Bowl XLVIII with the Seahawks then lost Super Bowl XLIX the following year. He retired after the 2015 season and sat out all of 2016 before signing with his hometown Oakland Raiders. His second season there ended after six games because of a groin injury that required surgery.

In a video posted to YouTube by Beast Mode Productions on Monday night -- the caption says the interview took place "a few days ago" -- Lynch was asked about a new opportunity and why he'd consider returning to Seattle. He responded: "We got history there. We got unfinished business."

Asked about that remark, Carroll said: "He's highly motivated to do everything you can do in this game. He really is. He wants to do everything you can possibly do. He knew he wasn't done. He got in a situation where he was injured, and he had to rehab and all that. It just didn't fit together right away. He's not done playing and he wants to go. This is his entrée and he's going to go for it. He won't hold back. He won't hold back one bit. We look forward to seeing what happens."

Only six players on the Seahawks' 53-man roster were teammates with Lynch during his first stint with the team: quarterback Russell Wilson, linebackers Bobby Wagner and K.J. Wright, wide receiver Tyler Lockett, tight end Luke Willson and Turbin.

Wagner was asked if Lynch can still be the Lynch of old.

"I definitely feel like anything this dude puts his mind to, get can get done," he said. "I'm excited to have him back, excited to see him run the ball. ... Whenever he puts his jersey and pads on, he's a guy that no one wants to tackle no matter how long he's taken off."

The Seahawks could finish as any among the NFC's Nos. 1, 2, 3 or 5 seeds depending on the outcomes of their Sunday night game against San Francisco as well as Green Bay at Detroit and New Orleans at Carolina.

They typically alternate which side of the ball gets to be introduced during pregame introductions at CenturyLink Field. It's the defense's turn this weekend, but Wright said they might have to make an exception. He wants an introduction for Lynch, knowing how loud the stadium will get.

Carroll was asked if he's gotten a sense of how much Lynch's return has energized the Seahawks' fan base.

"Honestly, I'm not surprised," Carroll said. "He's impacted a lot of people around here and people love the Seahawks. He's been something very special. I'm thrilled for the fans that they're having fun with it and all that. I'll be really thrilled if he knocks out 110 in the ballgame."