The Twins selected Lee's contract from Triple-A St. Paul on Wednesday.
Lee will get his first taste of major-league action, filling Royce Lewis' (groin) spot on the active roster. The 23-year-old has been lighting it up at St. Paul, owning a 1.029 OPS and a .306 ISO across 94 plate appearances. He should mix in with Jose Miranda at third base while Lewis is on the IL.