McCormick injured his ankle in Monday's Week 15 game against Atlanta.
McCormick had his ankle rolled up on during a second-quarter carry and went to the locker room shortly thereafter. The Raiders announced near the midway point of the period that he's questionable to return. Prior to his exit, McCormick rushed seven times for eight yards and caught both of his targets for 17 yards. If McCormick is unable to return Monday, Alexander Mattison figures to work as Las Vegas' lead back, with Ameer Abdullah contributing behind him.