RENTON, Wash. -- Michael Bennett, the Seattle Seahawks' ninth-year defensive lineman, has been around long enough to know how it works in the NFL.

Getting younger and cheaper is always the name of the game.

"I think things are going to be different," he said recently when asked about the future of Seattle's defense beyond the 2017 season. "That's a part of the NFL. The NFL is a transitional sport and transitional teams. Every year, there's a new transition and new guys and new coaches and new staffs. It's about who can win and how fast they can win, and it's about 'can we get a guy cheaper than the guy in front of him?' This is bound to happen and everything has a shelf life, and us as players, we have shelf lives and our team together has a shelf life."

Several Seahawks might be nearing the end of their shelf life in Seattle as age, salary, injury, contract status and/or performance -- the usual suspects -- could work against their return to the team in 2018.

With the playoffs up in the air for Seattle, here's a look at nine players who could be playing their final game with the Seahawks in Sunday's regular-season finale -- or in the case of three injured stars on defense, might have already done so.

Pending unrestricted free agents

TE Jimmy Graham: When Graham scored a 3-yard touchdown on his lone catch in Seattle's win against Dallas last week, it was emblematic of his season. He has 10 touchdown receptions to rank in a tie for second among all players and first among tight ends. But his 475 yards through 15 games are well off his 2016 total of 923. That includes a net of 2 yards on two receptions during the Seahawks' past three games as Graham has all but disappeared from their offense save for his latest touchdown. He has also dropped seven passes, according to ESPN charting, which is tied for second most among all players. Graham's long-awaited emergence as a red zone threat will no doubt be enticing to the Seahawks. At the same time, he's 31 with a serious knee injury in his recent past and could potentially still command a contract that pays him close to the $10 million his previous deal averaged.

DT Sheldon Richardson: He's been much more impactful than his lone sack would suggest. Richardson has been strong against the run and has made two of the more significant defensive plays of Seattle's season -- an interception against the Rams in October and a forced fumble near the goal line against Philadelphia in December. The Seahawks probably wouldn't have given up a second-round pick to acquire Richardson in a trade right before the season if they didn't think they'd have a decent chance of re-signing him. How much north of, say, $10 million will they be willing to go? The Seahawks pulled the trigger on the Richardson trade after learning that rookie Malik McDowell would be sidelined following an ATV accident. It's unclear if McDowell will ever be able to play. His status will presumably affect Richardson's situation to some degree.

WR Paul Richardson: He's had a breakout season in the fourth and final year of his rookie contract, catching 44 passes for 703 yards and six touchdowns. The yardage and touchdown totals are more than what he accumulated over his first three seasons combined. Richardson has emerged as Seattle's No. 2 receiver this season behind Doug Baldwin and ahead of Tyler Lockett. Equally significant: he's only missed one game over the past two seasons, showing durability that should mitigate some of the concerns about the injuries that slowed him earlier in his career. In a recent Insider piece for ESPN.com, Field Yates identified Richardson as a pending free agent who could command a bigger deal than most people assume.

Situations affected by injuries

CB Richard Sherman: He might have made this list even if he were healthy. After all, the Seahawks openly shopped Sherman last offseason but hung onto him when no favorable deal materialized. His injury situation adds to the uncertainty. Sherman suffered a ruptured Achilles in Week 10, ending what could have been another All-Pro season -- and possibly his distinguished Seahawks career. Sherman will be 30, entering the final year of his contract and coming off a serious injury. He's scheduled to count $13.2 million against the 2018 cap and would save Seattle $11 million if he were released or traded.

SS Kam Chancellor and DE Cliff Avril: They're in similar situations, having suffered neck injuries that could keep them from playing again. Coach Pete Carroll has been vague about the exact nature of their injuries but has said that both face uncertain football futures. Chancellor just signed an extension with Seattle last offseason and Avril is signed through 2018. Avril's age -- he turns 32 in April -- and contract situation would have made him a potential salary-cap casualty even if he hadn't injured his neck.

Potential cap casualties

DL Bennett: The operative word here is "potential." This one is by no means certain. Bennett is still a disruptive force. He ranks second on the team with 8.5 sacks and is again playing more than any other Seahawks defensive linemen -- by a wide margin -- despite dealing with injuries to his foot and more recently his knee. The Seahawks just gave him a contract extension last December and would incur a significant amount of dead money -- more than $5 million -- if they were to release him this offseason, leaving the net savings at a little more than $2 million (or more if they were to designate him a post-June 1 cut and thereby push some of the dead money to next year). But that might be enough given that Bennett will be 33 next season, an age when his skills could rapidly decline.

P Jon Ryan: This is another one that's possible but not a given. Ryan, 36, is the longest-tenured Seahawk and is two years into a four-year extension he signed in 2016. The Seahawks would eat $1.2 million in dead money by releasing him this offseason while saving a net $2 million.

CB Jeremy Lane: The Seahawks cutting Lane seems like a foregone conclusion. He's been benched twice this season and was traded to the Houston Texans only to return to Seattle because of a failed physical. His contract includes a $7.25 million cap charge for next season, which is obviously prohibitive for a backup cornerback.