The A's have also created the role of coordinator of instruction, to be held by former big leaguer and University of Pacific baseball coach Ed Sprague, who served as a consultant to the A's player development staff in 2016.
Gil Patterson (Minor League pitching coordinator), Jim Eppard (Minor League hitting coordinator), Juan Navarrete (Minor League fielding coordinator) and Craig Lefferts (Minor League rehab coordinator) are set to return in their same roles.
At Nashville, Christenson will be joined by pitching coach Rick Rodriguez, hitting coach Eric Martins, athletic trainer Brad LaRosa and strength and conditioning coach Henry Torres.
Midland, meanwhile, will see Fran Riordan replace Christenson as manager. Riordan managed at Class A Beloit the previous two seasons, following 14 years as a manager in independent leagues. John Wasdin (pitching coach) and Brian McArn (hitting coach) return to Midland's staff, as does athletic trainer Justin Whitehouse. They'll be joined by new strength and conditioning coach Matt Rutledge.
Several familiar faces will be back at Class A Advanced Stockton, including manager Rick Magnante, pitching coach Steve Connelly, hitting coach Tommy Everidge and strength and conditioning coach Sean Doran. Beloit gets a new manager in Scott Steinmann, who will have Don Schulze (pitching coach), Juan Dilone (hitting coach), Brian Thorson (athletic trainer) and Omar Aguilar (strength and conditioning coach) on his staff.
Aaron Nieckula, who will also continue his role as Minor League field coordinator, returns to Class A Short-Season Vermont as manager, with Carlos Chavez as his pitching coach and Lloyd Turner as his hitting coach. Toshi Nagahara (athletic trainer) and J.D. Howell (strength and conditioning coach) will join them.
The A's Arizona Rookie-level affiliate will employ the same staff: Webster Garrison (manager), Gabriel Ozuna (pitching coach), Ruben Escalera (hitting coach), Chris Lessner (athletic trainer) and Terence Brannic (strength and conditioning coach).
Elsewhere, Nate Brooks -- formerly the system-wide rehab coordinator -- has been promoted to medical coordinator. Travis Tims takes over Brooks' prior role, while A.J. Selliger assumes the strength and conditioning coordinator position.