Arizona removed their ex-general manager Kevin Towers from the position back on September 5.
Stewart, 57, is a former Major League Baseball player and has spent time as a pitching coach and a player agent since then. He was initially hired into the managing side of baseball in 1997, when then-Padres GM Kevin Towers hired him to be his assistant. However, he then he moved positions out of the front office and became their pitching coach.
Stewart left San Diego in 1998 to pursue another career in the front office, and was hired to become the assistant general manager of the Toronto Blue Jays. Again he moved positions, becoming their pitching coach as well. After the 2001 season, the Blue Jays passed on Stewart as their next general manager and he left the organization. He then went to Milwaukee to become their pitching coach for 2002.
Since leaving coaching following the 2002 season, Stewart has worked as a player agent for his own sports agency named Sports Management Partners, while also overseeing the Dodgers farm system. He currently represents Major League players such as Dodgers outfielder Matt Kemp and Dodgers pitcher Chad Billingsley. If he is to get the job in Arizona, he told the San Francisco Chronicle that he would move the business over to former teammate Dave Henderson.
Many people speculate that the hiring of Stewart will keep Kevin Towers in the organization. The two worked for each other in San Diego. He also has known Tony La Russa, Chief Baseball Officer of the Diamondbacks, for 26 years. Their relationship has likely led to his hiring.