The COVID-19 list was created this summer for a player who either tests positive for or who has been quarantined after having been in close contact with an infected person or persons.
Players will remain on the list until they are medically cleared to return.
Allen, 28, is a former third-round pick of the Chargers back in 2013. He was entering the final year of his five-year, $46.671 million contract that included $20 million guaranteed when the Chargers signed him to a four-year, $80 million extension.
In 2020, Allen has appeared in 14 games for the Chargers and caught 100 passes for 992 yards and eight touchdowns.