Alcantara -- ranked by MLBPipeline.com as the A's No. 24 prospect -- allowed eight runs in two innings against the Rangers on Friday, while Hahn managed to hold the Rangers to two runs in the six innings that followed.
"Give Raul a little bit of a break," A's manager Bob Melvin said. "That was a tough one for him. Now, one start and out of the rotation, that's kind of difficult, but with us, these things often flip, when you're trying to play a hot hand."
More changes will come when Sonny Gray, recovering from a lat strain, returns.