Willingham had been on paternity leave following the Wednesday birth of his son.
To open a roster spot for Willingham, outfielder Ben Revere will be optioned to Triple-A.
Willingham could add some life to what has of late been an otherwise anemic offense. Even after missing the last three games, Willingham leads the team in home runs (5) and RBI (13).
The Twins have scored just 22 runs during their current six-game losing streak.