Four years ago, a storied starting pitcher, plucked from a National League West rival and fresh off signing the biggest contract of his life, sat on a dais at Chase Field and extolled the virtues of living in Arizona. Zack Greinke loved the oranges and purples in the Arizona sky at dusk. “I think the sunsets here are fantastic,” he said after signing a six-year, $206.5-million deal in December 2015.



Greinke is no longer an Arizonan, the Diamondbacks having traded him to the Astros in July in exchange for prospects and salary relief. Even as Diamondbacks general manager Mike Hazen defends it as the right move — a view many in the game share with him — he felt like it left his team missing something at the top of the rotation. Perhaps it wasn’t a need for this particular offseason when the outfield seemed a more pressing concern. But it was something to address down the road.



Instead, the Diamondbacks found themselves again hosting a...