Blackley, who represents the fourth Australian to have appeared on the A's roster this year, spent part of the 2010 season in Oakland's organization. He began the 2012 campaign at Triple-A Fresno, posting a 0.39 ERA in four games -- three starts -- before being selected by the Giants, for whom he allowed five earned runs in five innings. San Francisco designated him for assignment on Sunday.
A's manager Bob Melvin, briefly acquainted with Blackley while both were with the Mariners and D-backs, said the southpaw will mainly be used for length out of the bullpen upon his arrival. Blackley is expected to report Wednesday in Texas, at which time the A's will make a corresponding 25-man roster move. To clear a spot for him on the 40-man, Joey Devine was transferred to the 60-day disabled list.
Oakland is already equipped with four left-handed relievers, meaning one of them is likely to be sent out Wednesday. Pedro Figueroa, who has allowed a run in each of his last two outings, is a strong possibility.
Major League Baseball is considering picking two teams to open the 2014 season in Australia, and the A's are said to be extremely interested. Recent acquisitions -- Blackley joins fellow Aussies Grant Balfour, Luke Hughes and Rich Thompson in the A's organization -- suggest they're doing their best to make it happen.
"We're trying to get them all," Melvin joked.