Mills and Francona played together at the University of Arizona and on the Montreal Expos while also coaching together in Philadelphia and Boston. Mills managed the Astros from 2010 to 2012. Houston, at 55-107, had the worst record in the league in 2012.
Sandy Alomar Jr, who was the interim manager of the Indians in the final six games of the 2012 season, is the only other coach who has agreed to join Francona's staff.
The Indians finished in fourth place in the American League Central with a record of 68-94, 25 games behind the first place Detroit Tigers.
Cleveland hired former Red Sox Manager Terry Francona at the conclusion of the 2012 season. Francona has managed 12 seasons in the majors and has a 1,029-915 career record. He also won two World Series titles with the Boston Red Sox.