A's bring up Blackley, option Carignan

ARLINGTON -- The A's officially swapped a righty reliever for a lefty one on Wednesday, bringing up Travis Blackley and optioning Andrew Carignan to Triple-A Sacramento.

Blackley, whom the A's claimed off waivers from the Giants on Tuesday, gives Oakland five southpaws in its bullpen. Though a rarity to have so many lefties in stock, this is nothing new for Oakland, which at one point last season also employed five.

"At some point in time, you just use your best pitchers that you feel you have at the time," manager Bob Melvin said. "There's always going to be some trial and error, and that's just where we are right now."

Blackley, who has made more starts (eight) than relief appearances (four) in the big leagues, represents a true length option, as Melvin also noted.

"Length is length, and I think Travis gives us, at this point, the most length, coming from a natural starter who can give you more than two innings," he said of the Australian native. "This is a guy who could really give you four or five innings if you need it."

Carignan was just five days into his second stint with the A's this season before being demoted. The right-hander appeared in two games over that span, allowing two runs on two hits with three walks in two innings.