Gibson, the 25-year-old right-hander picked 22nd overall in the 2009 First-Year Player Draft, is scheduled to start for the Twins on Saturday at Target Field against the Royals. He took the roster spot of left-hander Pedro Hernandez, who was optioned to Triple-A Rochester, and will wear uniform No. 44.
Gibson made 15 starts for the Rochester Red Wings this season, going 7-5 with a 3.01 ERA, 79 strikeouts and 28 walks in 92 2/3 innings.
Meanwhile, in the Minors, No. 2 Twins prospect Byron Buxton was promoted on Sunday night from Class A Cedar Rapids to Class A Advanced Fort Myers in the Florida State League.
Buxton, drafted second overall in last year's Draft, has earned his status as one of the top prospects in baseball. The 19-year-old outfielder tore up the Midwest League in 68 games this season, batting .341 with a .431 on-base percentage, .559 slugging percentage, eight homers, 10 triples, 15 doubles, 55 RBIs and 32 stolen bases.
Buxton spent last season between the Twins' two Rookie affiliates, posting a .248/.344/.448 line with 19 extra-base hits, 20 RBIs and 11 steals in 48 games. He was ranked 18th overall on MLB.com's top 100 prospects list and second in Minnesota's farm system behind third baseman Miguel Sano, who slugged his way out of Fort Myers and on to Double-A New Britain's roster earlier this season.
Adam Berry is a reporter for MLB.com. Follow him on Twitter at @adamdberry. This story was not subject to the approval of Major League Baseball or its clubs.