Not for the first time, Dan Straily knew before he stepped on the mound that he was going down to the minor leagues after the game.

It didn't deter him at all as the A's fifth starter allowed just two hits in 61/3 innings in a 2-1 win over Pittsburgh on Tuesday before being moved to Triple-A Sacramento. With the All-Star break coming up, the A's don't need a fifth starter until July 23.

In the meantime, the club will have Sonny Gray. The former first-round draft pick out of Vanderbilt was scratched from his start for the River Cats and will join the A's for their series finale against the Pirates on Wednesday.

He likely is up for a stay of a couple of weeks until Straily, who is 5-0 in his last nine starts, returns to the rotation.

"It's an audition, that's the thinking behind it,'' manager Bob Melvin said of the promotion of Gray. "This is certainly not the last time he's going to be here. No question. He can get some firsts out of the way.''

Gray is 8-5 with a 2.81 ERA at Sacramento. Scouts have been effusive over the way he's been pitching the last six weeks or so, but the A's don't have an opening for a starter. He'll be the long reliever, and after that, who knows?

"You never know what will happen,'' Melvin said, talking about the audition. "We'll see how it plays out.''

Straily, now 6-2 with a 4.28 ERA, had to wait a little while to get the start. One hour, 42 minutes to be exact. The Pirates, told to expect a heavy thunderstorm, held off first pitch that long until it became clear that despite thunder and lightning, the rain was someplace else. No precipitation fell until almost midnight, by which time the game was over, even figuring in the lengthy delay.

The second-year right-hander said waiting for the game to start, his teammates turned the clubhouse into "the Oakland Zoo.'' He said there was "bowling going on and bottle-cap baseball'' and other bits of mischievous time-killers that meant "I had to leave the room at one point to focus.''

Once the game started, there was nothing wrong with Straily's focus. He fluttered a changeup that Pedro Alvarez hit into another time zone, but it came with no one on base and was the only hit of note for the Pirates on the night. The next time up, Straily said he threw the first curve ball he's thrown in a game in two seasons, and he struck Alvarez out with it.

"Straily was terrific again,'' Melvin said. "There was the one pitch he'd like to have back, that's it. He'll go down now because we don't need a fifth starter until the 23rd, but it's nothing that he's done.''