More speculation on the endless mystery of Marshawn Lynch: NFL.com’s Ian Rapoport, via anonymous sources, wrote Sunday that the Seahawks’ star may retire after the 2014 season, at least partly due to health. That would mean walking away from a $5 million base salary due him in 2015, but his increasingly public efforts to play through pain suggest that it is a plausible reason.

Nothing is imminent, or on the record, but Lynch, 29 in April, did tell some of his teammates after the Super Bowl win that he was contemplating retirement. But that was later seen by many as an attempt to create leverage for more money, which developed into an eight-day holdout from training camp.

Lynch came in after getting $1.5 million more when the Seahawks guaranteed bonus money that had yet to be earned, some advanced from his scheduled earnings in 2015.

Rapoport also identified part of the physical problems Lynch is having: Compression of cartilage in his spinal cord. During the game in Kansas City, Lynch stayed on the sidelines at halftime to save energy and receive treatment on his back, prompting national speculation about division between Lynch and coach that was unfounded.

But if he is healthy enough for another year, Rapoport speculated that he might request a trade to any team that would hire Seahawks assistant Tom Cable as a head coach. Cable, a Snohomish native and former head coach in Oakland, may be an attractive hire because of all the success Seattle has had with his specialty: A dominant run game despite average line talent and the relentless Lynch.

Bringing Lynch along for even a year figures to enhance Cable’s resume, and speaks well to the relationship he has fostered with Lynch and his outlier personality.

Coach Pete Carroll said recently that the Seahawks want Lynch for as long as he can play, attempting to scotch previous speculation that their differences might impel the Seahawks to trade or waive him before 2015.

The Seahawks (8-4), winners of five of their past six after beating the 49ers in Santa Clara 19-3 Thursday, play the Eagles in Philadelphia Dec. 7.