Allen didn't participate in Thursday's practice due to a hamstring injury, Jeff Miller of the Los Angeles Times reports.
Allen appeared on the Chargers' injury report earlier this season due to a knee issue, but the hamstring injury is a new concern for the wideout. He may have tweaked something in the aftermath of Wednesday's practice, as the Chargers didn't include him on their initial Week 8 injury report. Allen's status now becomes something his fantasy managers need to monitor heading into Sunday's game against the Bears.