The Twins announced the moves before Friday's day-night doubleheader.
Doumit says he felt fine on Friday and lobbied to stay on the active roster. He was injured Sunday when he took a foul off the mask in the ninth inning against the Houston Astros and felt nauseated on the flight to Kansas City afterward. He says he didn't tell anyone or think much of it. But he began to feel ill during Wednesday's game and had to exit.
Willingham had surgery July 3 to repair a medial meniscus tear in his left knee. He appeared in three rehab games for Triple-A Rochester.