Garvin Alston, who spent the previous six seasons as the organization's Minor League pitching rehab coordinator, has been named Minor League pitching coordinator. Greg Sparks will serve as Minor League hitting coordinator, after three seasons as hitting coach at Triple-A Sacramento.
Aaron Nieckula joins them as Minor League field coordinator and will oversee Minor League Spring Training, extended spring camp and instructional league, and Juan Navarrette returns for his 21st season with the organization as he continues his services as the Minor League defensive, baserunning and bunting coordinator.
Nieckula also will manage the A's short-season Class A club in Vermont.
It's Craig Lefferts, who spent the previous 12 seasons as a pitching coach in the A's farm system, who is replacing Alston as Minor League pitching rehab coordinator.
Steve Scarsone is back for his third season as manager of the A's Triple-A affiliate, which has moved from Sacramento to Nashville. His staff will include hitting coach Webster Garrison and pitching coach Don Schulze, mainstays in the A's organization but new to the Triple-A level.
Former A's player Ryan Christenson, who led Class A Advanced Stockton to the postseason this past season, takes over as manager at Double-A Midland, overseeing a bevy of prominent prospects, including Daniel Robertson, Renato Nunez and Matt Olson. John Wasdin will be Christenson's pitching coach, and Eric Martins, a longtime scout for the A's, will serve as hitting coach.
Stockton will be led by Rick Magnante, who managed Class A Beloit last season. Rick Rodriguez, entering his 31st season in the A's organization, including two as bullpen coach in Oakland from 2011-12, has been named the Ports' pitching coach. Brian McArn returns for his fourth season in Stockton as hitting coach.
In the lower ranks of the Minors, Fran Riordan will manage Beloit, with Steve Connelly acting as his pitching coach and Lloyd Turner his hitting coach.
Ariel Prieto, who just finished his third season on the A's big league staff as a coach and interpreter for Yoenis Cespedes, will remain in Oakland's organization, despite Cespedes' absence, and serve as pitching coach for the A's affiliate in the Rookie-level Arizona League.
Ruben Escalera will be the manager, and Juan Dilone has been named hitting coach.