Seattle Seahawks suffered a major setback in their NFC West showdown with the Los Angeles Rams on Sunday when lead running back Kenneth Walker III sustained a non-contact oblique injury in the first quarter. The incident occurred during a 6-yard run midway through the quarter, causing Walker to clutch his left side and fall to the ground.

The Seahawks listed Walker as doubtful to return with an oblique injury, which is a significant blow for the team. At 6-3, Seattle is currently tied with the San Francisco 49ers atop the NFC West. Walker had been instrumental in leading the team through nine games with 770 yards from scrimmage and seven touchdowns, building on a strong rookie campaign that produced 1,215 yards from scrimmage and nine touchdowns.

The severity of Walker’s injury is not yet clear, but it has left rookie running back Zach Charbonnet to take over as Seattle’s lead back in his absence. It remains to be seen how well Charbonnet will handle the increased workload and whether he can maintain the same level of productivity as Walker. However, given his impressive performance so far this season, it seems likely that he will do his best to step up and fill Walker’s shoes.