What is the fine-grained topic of the following text: 2 prospect when he was traded by Houston along with right-handed pitcher Adrian Houser, outfielder Domingo Santana and left-handed pitcher Josh Hader to the Milwaukee Brewers for outfielder Carlos Gomez, right-handed pitcher Mike Fiers and other considerations on July 30, 2015. Only return the topic.
Trade between Houston and the Milwaukee Brewers in 2015