Why in the world would you want to trade Zack Greinke? It’s not like it hasn’t happened before — there was even that brief, glorious half-season when Greinke was with the Los Angeles Angels of Anaheim that everyone has consigned to the memory-hole — but the last two teams that traded the quixotic right-hander, the Milwaukee Brewers and the Kansas City Royals before them, did so as part of a rebuilding process. The Brewers dealt Greinke to the Angels at the 2012 trade deadline, and the Royals traded him in the 2010 offseason to those very same Brewers. Both teams had reasons for making those deals: They needed players to build the core of the next successful Kansas City and Milwaukee teams. The Kansas City-Milwaukee deal netted the Royals Lorenzo Cain, Alcides Escobar, and Jake Odorizzi (who would be part of the Wade Davis-James Shields trade). The Milwaukee-Anaheim deal netted the Brewers Jean Segura, who would be dealt to the Arizona Diamondbacks for Chase Anderson, who had an amazing breakout season last year for the first decent Brewer team in far too long. Both of those teams were in much different circumstances than the Arizona Diamondbacks are right now (the Diamondbacks don’t even have Jean Segura anymore; they sent him north to Seattle for Ketel Marte and Taijuan Walker in a trade that worked out fairly well for both sides). Right now, the Diamondbacks are a success story — a team that won 93 games after everyone said they should have burned the team down and started a from-scratch rebuild; a team that, yes, got swept out of the divisional round by a Dodger club that lost the World Series to the Houston Astros, but still a team with a lot of promise. They had a great pitching staff and, reliably-near MVP Paul Goldschmidt aside, they could have used some more help at the plate — even if their light-hitting lineup did provide good defense.