CHICAGO -- The Cubs have hired PJ Mainville, who was the D-backs' assistant athletic trainer the last two seasons, as the team's head athletic trainer, replacing Mark O'Neal, who is staying in a new role as a medical administrator.

Mainville, 37, worked in the D-backs' Minor League system from 2007-10 before he was named assistant athletic trainer to the big league team. He was a Minor League trainer in the Orioles' organization for nine years before joining Arizona.

O'Neal has been the Cubs' head athletic trainer since 2004.