Blackburn's contract was selected by the Athletics to start Wednesday's game against the White Sox, Martin Gallegos of MLB.com reports.
Blackburn began the season at Triple-A Las Vegas and posted a 4.97 ERA and 1.60 WHIP in 88.2 innings across 17 appearances (16 starts). He hasn't fared particularly well in limited major-league action across the last two seasons, recording a 13.50 ERA and 2.25 WHIP in 13.1 innings during five appearances (two starts) over that span.