Miller's third-largest brew has been declining since the 1990s as consumers switched to light beers.
The 29-year-old brand manager promises a "no stone unturned" approach to coming up with a strategy and positioning for MGD.
Mr. Haley started at Miller in 2001 and brings to the job brand management experience on smaller Miller brands including regional brews Henry Weinhard's and Leinenkugel's, as well as Australian import Foster's.
Mr. Haley relishes the competitive nature of the beer business. And he sees plenty of future challenges facing all young marketing executives. Those include finding ways to dig up more granular consumer insights and selling to an increasingly diverse population.