Scott Emerson, coming off his 10th season as a pitching coach in the A's farm system, has been named Minor League roving pitching instructor in place of Gil Patterson, who left Oakland's organization after six seasons to become the Yankees' director of pitching.
Marcus Jensen will serve as the A's Minor League roving catching instructor, while also managing the A's affiliate in the Arizona Rookie League for the fifth consecutive season.
At the Triple-A level, Steve Scarsone takes over as manager in Sacramento, after spending the previous two years at Double-A Midland. Former River Cats manager Darren Bush, meanwhile, will serve as bullpen coach for the A's, a spot vacated by Rick Rodriguez, who will now enter the role of Sacramento's pitching coach. Greg Sparks will return as the hitting coach.
In the wake of Scarsone's promotion, Aaron Nieckula was elevated to manager at Midland after seven seasons as a manager with the A's Class A affiliates. He'll be joined by Don Schulze, who returns for his third season as pitching coach, and Brian McArn, who has been named hitting coach after spending the last two seasons in the same capacity with Class A Stockton.
It's there where Webster Garrison will return to manage the Ports for a third straight year. Jimmy Escalante begins his seventh season as pitching coach in the A's farm system, his first with the Ports, and Haas Pratt was named hitting coach after three seasons at Kane County and two with Burlington.
Ryan Christenson, who played for the A's from 1998-2001, has been named manager for the A's new Class A affiliate at Beloit (Wis.), his first Minor League managing assignment. John Wasdin has been named pitching coach after spending the last two seasons at Vermont (2011) and Burlington (2012), and Casey Myers will serve as hitting coach after filling that capacity at Vermont (2011-12) and Vancouver (2009-10).