Is J.T. Ginn the Ace of the A's Rotation?

While he didn't complete the job on Monday night, losing a no-hitter and suffering a walk-off defeat in the ninth, J.T. Ginn has been on another level his last three starts, holding a 1.23 ERA. 

Aaron Civale has been tremendous all season with a 2.70 ERA, while Ginn's is not down to 2.98, but the argument for Ginn would be that he's able to go much deeper into games. In two of these three outings he's completed eight innings. Civale has been a steady five, maybe six frames each game. 

Who is your ace right now?