The 49ers are expected to activate Aiyuk (undisclosed) from the reserve/COVID-19 list Tuesday, Chris Biderman of The Sacramento Bee reports.
Aiyuk spent two stints on the reserve list, but it was never revealed whether he tested positive for the virus or was merely a close contact of someone who did. In any case, as long as he's back on the active roster by Thursday, he'll join his teammates for practice as the 49ers prepare for Monday's game against the Bills.