Austin Adams throws like 95-96. 28 K in 18 IP. That's a pretty live arm. Mason is low 90s.
The Twins are in a win-now situation this season, which is a good thing. That, to me, means just call up the guys that give you the best chance to win when they are asked to contribute. It's not about development at this point in the big leagues as it was when the team was bad. Adams has been good in AAA. He's got experience.
Also, since he is out of options, he's the kind of guy that you don't worry about DFAing when he isn't needed in the big league roster. And he probably clears and stays.
It seems a bit contradictory to me to say that he's the best player to help a contending team right now, while also saying he'd clear waivers if DFA'd. By definition, wouldn't he be claimed by a contender if he's good enough to help a contender win games?