The A’s traded lefty Dillon Overton to Seattle on Thursday, one day after he was designated for assignment to clear roster space for Adam Rosales.
In return the Mariners sent Oakland minor league catcher Jason Goldstein, a ninth-round pick in last June’s draft out of the University of Illinois.
Overton began last season as the A’s No. 8 prospect as ranked by Baseball America. He enjoyed a strong season with Triple-A Nashville and made his major league debut in June. But Overton struggled over four stints with the big club, going 1-3 with an 11.47 ERA in seven games (five starts). He also allowed 12 home runs in 24 1/3 innings, a rate of 4.4 homers per nine innings that ranked as the highest in major league history for a pitcher with more than 20 innings pitched.
Goldstein hit .279 with no homers and six RBI in 19 games split between rookie ball and short-season Single A. His pro debut was delayed after the draft due to a torn hamstring.
Overton is headed to an AL West rival after it appeared at this time last year that he might be a future piece of the A’s rotation. But young starting pitching appears to be one of Oakland’s biggest strengths after they’ve built up that area through the draft and numerous trades.
Sean Manaea is expected to help anchor this year’s rotation in his second season. Jharel Cotton has a great shot at the rotation after a promising September. Another wave of prospects — including lefty A.J. Puk and right-handers Grant Holmes, Frankie Montas and Daniel Gossett — all dot the A’s most recent top-10 prospects list by Baseball America.