Rivera walked into the clubhouse with his luggage about two hours before Sunday's game against Detroit and was in the lineup batting ninth. Utility infielder Matt Tolbert was sent to Triple-A to make room on the roster. He'll be brought back next month once the roster can be expanded.
Manager Ron Gardenhire said Mauer was feeling better in the morning and won't be placed on the disabled list, but this is his fifth straight game missed.
Right fielder Michael Cuddyer was also improving and available to pinch hit against the Tigers. He's been bothered by a sore wrist.