The San Francisco 49ers came out with a win against the Seattle Seahawks on Thursday Night Football, but not without an injury to one of their key offensive players.

“The NFL’s leading rusher, 49ers RB Jordan Mason, is believed to have suffered a sprained AC joint during Thursday night’s win at Seattle that is not considered serious, but he will undergo further testing today, per sources,” ESPN's Adam Schefter tweeted on X, formerly Twitter.

Mason returned for one play in the second half but then missed the rest of the game. Mason had been doing a solid job replacing Christian McCaffrey while he's out, and hopefully, his injury isn't serious.

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San Francisco 49ers quarterback Brock Purdy (13) hands the ball off to running back Jordan Mason (24) during the first half against the Seattle Seahawks at Lumen Field.
Steven Bisig-Imagn Images
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Jordan Mason has stepped up in a big way for the 49ers while Christian McCaffrey was out, as he's been the leading rusher in the NFL through six weeks. With Mason's future availability in question and no timetable for McCaffrey, Issac Guerendo will have to take over in the backfield.

There is no set date for McCaffrey's return, but he's been feeling good and ramping up his activity over the past few weeks. There have been no flare-ups for the running back, which means that a more realistic time for him to return would be around Week 9.

The 49ers have been up and down this season with injuries and inconsistent play, but hopefully, they can get into a rhythm soon. Their next test will be against the Kansas City Chiefs, who defeated them in the Super Bowl last season. The Chiefs are trying to manage their own injuries on offense as well, so the game may come down to who's the healthiest.

For now, the 49ers are trying to figure out if Mason will have to miss any time, but they have the backup if needed.