Alcantara, 23, has been absolutely dominant for Triple-A Nashville following his July promotion from the Double-A level, pitching to a 1.18 ERA across eight starts, with six earned runs allowed in 45 2/3 innings. He has 32 strikeouts in that span, next to just three walks.
Alcantara landed in Oakland's organization with outfielder Josh Reddick as part of the 2011 trade that sent reliever Andrew Bailey and outfielder Ryan Sweeney to Boston. He appeared to be on the fast track to the big leagues before he was slowed by Tommy John surgery in 2014.