McGloin was injured on a late hit by Denver Broncos defensive end Jared Crick and is questionable to return. Cook, the Raiders' fourth-round draft pick out of Michigan State, made his NFL debut after not being active all season and he completed two of his first three passes for eight yards.
McGloin, meanwhile, was just six of 11 for 21 yards as the Raiders trailed, 17-0, at halftime. He was ruled "questionable" to return as he went to the locker room after being worked on by trainers on the sidelines.
If the Raiders (12-3) lose to the Broncos (8-7), and the Kansas City Chiefs (11-4) win at the San Diego Chargers (5-10), Oakland falls to the No. 5 seed in the AFC playoffs and play at the Houston Texans (9-7) as a wild card next weekend. But if the Raiders come back to win in Denver, they would win the AFC West and get the No. 2 seed in the conference with a first-round bye and play host to a playoff game.