Arnette, the 19th overall selection out of Ohio State in April's draft, was already on injured reserve after undergoing surgery on his right thumb the week of Sept. 30. Arnette injured his right hand in training camp, and he was playing with a cast on it when he landed awkwardly on a sideline tackle at the New England Patriots in Week 3.
The rookie has 13 tackles, 11 solo, and a pass defensed in three games as a starter.
The Raiders also took defensive tackle Maurice Hurst off the reserve/COVID-19 list after placing him there on Oct. 6.
NFL Network first reported the news of Arnette being placed on the reserve/COVID-19 list.