The Raiders on Thursday placed linebacker Cory Littleton on the Reserve/COVID-19 list.
He joins right tackle Trent Brown, who was placed on the list for a second time after experiencing lingering symptoms from his initial bout with the virus in October.
It is unclear if Littleton tested positive for the virus or was in proximity with somebody who tested positive. He practiced Wednesday, but was not present at practice on Thursday.
If a player is deemed as a “high risk” close contact, he’ll have to stay away from the team for a minimum of five days and can return only after producing a series of negative tests.