Jon Heyman of CBS Sports first reported the sides had agreed to a deal.
Mayberry Jr. has played in the major leagues for five seasons. He played for the Philadelphia Phillies from 2009 to 2014. The team traded Mayberry Jr. to the Toronto Blue Jays before the Aug. 31 waiver trade deadline.
Last season with the Phillies and the Blue Jays, Mayberry Jr. hit .212 with seven home runs and 23 RBIs.
- Sarah Barshop