Rookie right-hander Liam Hendriks rejoined the rotation on Wednesday, giving the Twins a five-man rotation of Scott Diamond, Samuel Deduno, Brian Duensing, Cole De Vries and Hendriks.
But Esmerling Vasquez has been solid at Triple-A Rochester and is a candidate to be a September callup. The right-hander has a 2.86 ERA with 91 strikeouts and 36 walks in 94 1/3 innings with the Red Wings.
"If I have six people that can pitch, that would be wonderful, but right now we have five," Gardenhire said. "If that's the case, I wouldn't be afraid to do that at all, if we want to take a look at six guys."