If Marshawn Lynch is done, is Doug Martin ready for the role?

ALAMEDA, Calif. -- Has Marshawn Lynch played his final game in the NFL?

And if so, where do the Oakland Raiders go from here at running back in what is quickly becoming -- if it has not already passed that threshold -- a lost season?

Lynch suffered a groin injury during the Raiders' 27-3 loss to the Seattle Seahawks last week in London, and the Raiders placed the hard-charging 32-year-old on injured reserve on Monday. That makes Lynch ineligible to return until Week 16.

If the Raiders (1-5) continue their downward trajectory, who knows if Oakland's prodigal son would even want to play in Silver & Black again -- especially after the team traded away receiver Amari Cooper less than two months after dealing away edge rusher Khalil Mack. Numerous reports have suggested that safety Karl Joseph and cornerback Gareon Conley could also be on the trading block. Making those deals would mean the Raiders' first-round draft picks from 2014 through 2017 had all been traded away in short order.

Plus, Lynch told Las Vegas media he did not see himself playing in Southern Nevada when the Raiders relocate there in 2020.

Lynch's two-year contract is up after this season; it pays him a fully guaranteed $2.5 million in base salary after he restructured it this offseason, though it carries a salary-cap number of more than $4.45 million for 2018, per ESPN Stats & Information data. Lynch received a $1 million roster bonus on the 11th day of the league year, and he already has accrued $281,250 in roster bonuses ($46,875 per game on the Raiders' 46-man roster with a max of $750,000). He would miss out on $468,750 in bonuses if he did not play another game this season; he stood to earn up to $3.75 million in yards and touchdown incentives.

Lynch has been the Raiders' most productive and dependable player in coach Jon Gruden's offense -- even if Gruden has twice looked elsewhere at the goal line.

Lynch leads Oakland with 376 yards rushing, a 4.2 yards-per-carry average and three touchdowns, and he still was running hard with the Raiders trailing Seattle 27-0 in the fourth quarter when he was apparently injured.

Lynch was trying to pull his right leg out of the grasp of Seahawks cornerback Shaquill Griffin when linebacker Austin Calitro leveled Lynch, who landed awkwardly and stayed on the Wembley Stadium pitch for a moment before gingerly jogging off the field.

With Lynch out, veteran Doug Martin figures to become Oakland's No. 1 back.

But Martin has not been nearly as effective as the Raiders had hoped as a change-of-pace back. Lynch has avoided 25 tackles this season through Week 6, ranking fourth among all NFL running backs, per Pro Football Focus. Martin, though, was averaging just 0.07 forced missed tackles per touch after averaging a league-low 0.06 forced missed tackles per touch last year.

And the Raiders' offensive line is extremely beat up. Rookie left tackle Kolton Miller has surrendered six sacks over the past two games on a gimpy right knee. Pro Bowl left guard Kelechi Osemele has missed the past two games with a knee injury, and his backup, Jon Feliciano, left the London game with a rib injury. Right tackle Donald Penn is on IR with a groin injury, and rookie Brandon Parker is starting in his place.

At least the Raiders had the bye week to heal up.

Still, the Raiders can only bring back two players from IR, and Penn and defensive tackle Justin Ellis (foot) are thought to be the leading candidates.

The way Gruden saw things a few weeks ago, Martin was simply biding his time as Lynch excelled.

"We've got a good back over there, Doug Martin, who's ready to roll," Gruden said at the time. "And Doug can't get on the field."

He will now, after rushing for 99 yards on 27 carries and averaging 16.5 yards per game on the ground with three first downs this season.

The erstwhile "Muscle Hamster" had a good game at the Miami Dolphins in Week 3, rushing for 43 yards on nine carries in the Raiders' 28-20 loss.

"He was doing his thing, brah," Lynch said of Martin after that game. "You know what I'm talking about?"

Martin's 3.7 yards per carry average is his best since he averaged 4.9 yards for the Tampa Bay Buccaneers in 2015.

"I came into a new system this year, so OTAs, being in camp until now, I've gotten accustomed to the offensive line and doing camp with pads and practice," Martin said during the preseason. "So, I definitely feel like I'm where I need to be."

So too should Jalen Richard, used primarily as the third-down and pass-catching back, and possibly DeAndre Washington, who underwent a knee scope in the preseason and has yet to be activated for a game.

And if you're wondering about undrafted rookie Chris Warren, who led Oakland in preseason rushing, he is not eligible to play this season since he was placed on IR before the team's initial 53-man roster was announced on Sept. 1.

Lynch, you'll recall, famously retired once before, tweeting out a picture of his cleats hanging from a power line in the fourth quarter of Super Bowl 50.

Just over a year later, though, the Raiders acquired Lynch' rights from the Seahawks and he came out of retirement to join his hometown team. And earlier this season, Gruden said Canton was waiting.

"If that's not a Hall of Fame back, I don't know what is, honestly," Gruden said the day after Lynch rushed for 130 yards on 20 carries and caught three passes for 27 yards in the Raiders' 45-42 overtime victory against the Cleveland Browns on Sept. 30, Oakland's lone victory thus far.

"I mean, what he did yesterday, what he's done since he's been here, it's incredible. He wants the ball more, and more, and more ... this guy does not want to come off the field. He picked up six or seven blitzes yesterday too that no one's talking about. But some of the runs? Good night."

And maybe, just maybe, goodbye.