When Phillies' chairman David Montgomery took a medical leave of absence in 2014, Middleton assumed a more active role, overseeing on-field and business performance, and increased his shareholding to 48 percent. In 2015, Middleton became the public face of the Phillies' ownership group. Middleton committed that the Phillies would have a greater focus on analytics, which influenced the hiring of Andy MacPhail as president, and Matt Klentak as general manager.
