Lions head coach Dan Campbell said Thursday that Ragnow (pectoral) has been ruled out for Monday's game against the Seahawks, Tim Twentyman of the Lions' official site reports.
Ragnow, who is tending to a partial pec tear, will sit out the Week 4 game and then benefit from a Week 5 bye, potentially allowing him to return to the field Week 6 versus the Cowboys on Oct. 13. Graham Glasgow will likely slide over from left guard to start at center until Ragnow is ready to go. Ragnow is a pillar of the Lions' offensive line, so the team should prioritize his long-term health above all else.