The White Sox selected Baldwin's contract from Triple-A Charlotte on Friday.
Baldwin is starting at second base and batting eighth Friday in Kansas City in what will be his major-league debut. The switch-hitting infielder earned a promotion after slashing .324/.391/.460 with eight home runs and 17 stolen bases between Double-A Birmingham and Charlotte this season. Baldwin should see regular playing time for the White Sox, perhaps in a super-utility role rather than as an everyday option at the keystone.