In a season where injuries have been rampant, fantasy managers saw another top player go down on Thursday night. This time, 49ers running back Jordan Mason suffered a shoulder injury in the second quarter of a win over the Seahawks. He attempted to return in the third quarter, but he had just one rushing attempt before heading back to the sidelines.

Mason didn’t return to the contest.

49ers coach Kyle Shanahan didn’t offer any information about Mason after the game, but suggested more information will come out of his status on Friday.

“I don’t know, you never know,” Shanahan said. “I mean, adrenaline on these days during games is a little bit different. We’ll find out more tomorrow.”

Mason entered last night’s game as one of the top running backs in fantasy football and an absolute gift from the fantasy gods. After all, he replaced the best running back in fantasy football, Chrisitan McCaffrey, who hasn’t played a single snap this season due to Achilles issues, and performed amazingly.

The 49ers have a bye in Week 9, so it’s possible Mason could miss the next two weeks and return in Week 10. But here’s the problem … reports suggest McCaffrey could be back after the bye, too. In fact, SI NFL Insider Albert Breer told Charissa Thompson before Thursday’s game that McCaffrey has, “just started feeling like himself again last week,” and that the 49ers will start to ramp him up “over the last few days.”

So, in a worst-case scenario for Mason, he could come back as a backup to CMC.

In the interim, fantasy managers need to put in a waiver claim for Isaac Guerendo. He was solid in Mason’s absence, rushing 10 times for 99 yards (9.9 YPC) and just missed scoring a touchdown. If Mason were out the next two weeks, Guerendo would be a solid RB2.