Blackburn was traded to the A's on Saturday in exchange for Danny Valencia, Jeff Passan of Yahoo! Sports reports.
Acquired by Seattle in the Mike Montgomery trade this summer (along with Dan Vogelbach), Blackburn posted a 3.54 ERA, 1.25 WHIP and 27:9 K:BB in 40.2 innings with the Mariners' Double-A Jackson affiliate. The right-hander may not have a true plus offering, but his fastball, curveball and changeup are all serviceable pitches. He could be a rotation option for the A's in the second half of 2017.