The Royals have acquired outfielder Josh Willingham from the Twins for minor league pitcher Jason Adam in an attempt to bolster their offense for the stretch run.
The move was made shortly before the Royals opened a four-game series against AL West-leading Oakland on Monday night.
Willingham was hitting just .210 for the Twins this season, but his 12 homers in limited at-bats were appealing for a Royals club that has struggled to find power.
He hit a career-best 35 homers with 110 RBIs two years ago.
Adam is 5-9 with a 4.67 ERA with Double-A Northwest Arkansas and Triple-A Omaha this season.