There are no surprises on either team's list of players who will sit out Sunday's opener. Rookie E.J. Gaines is at cornerback for the Rams in place of Trumaine Johnson, previously ruled out and expected to miss a month with a knee injury.
Defensive end Everson Griffen starts for the Vikings after being listed as questionable due to illness.
Cornerback Maurice Alexander and defensive lineman Ethan Westbrooks, both rookies, also will not dress Sunday. Mason was a third-round pick, Alexander a fourth and Westbrooks, who was not drafted, outplayed Michael Sam for a backup spot on the Rams' defensive unit.