The Twins selected Cotton's contract from Triple-A St. Paul on Wednesday.
Cotton will rejoin the 40-man roster and 26-man active roster as a replacement for fellow reliever Juan Minaya, who was designated for assignment. Over his previous four stints on the Twins' active roster this season, Cotton made six appearances out of the bullpen and gave up two runs (one earned) while striking out 10 and walking six in 9.2 innings.