Jackson is expected to be placed on injured reserve after fracturing his scapula in Sunday's 41-10 loss to the Cardinals, Ian Rapoport of NFL Network reports.
Head coach Sean McVay said earlier Monday that Jackson would miss "a significant amount of time" with a shoulder injury, so Rapoport's report comes as little surprise. If Jackson is placed on IR as expected, either Logan Bruss or Justin Dedich will likely take over at left guard on an already depleted Rams offensive line.