Raiders safety Obi Melifonwu recently underwent knee surgery, according to Michael Gehlken of the Las Vegas Review-Journal. The operation is believed to have taken place last week.
The second-round pick missed part of training camp with an ankle injury. He played in only one exhibition game, making two tackles on 22 defensive snaps and an assist on 13 special teams snaps against the Cowboys.
He was not at the Oakland-Alameda County Coliseum on Thursday when the Raiders concluded their preseason against the Seahawks, according to Gehlken.
The Raiders likely will add a safety before Sunday’s season opener against the Titans with only three healthy players at the position. Shalom Luani, a seventh-round pick, is the only backup available behind starters Karl Joseph and Reggie Nelson.