The 35-year-old has three years and $104.5 million remaining on the six-year, $206.5-million contract he signed in Arizona before the 2016 campaign. It's possible that the team would have to retain a portion of the salary in any completed deal.
The five-time All-Star had a rocky start to his tenure in the desert, but has been solid on the mound over the last two seasons. Altogether, he's gone 45-25 with a 3.53 ERA, 1.13 WHIP, and 548 strikeouts in 568 2/3 innings with the Diamondbacks.
Over his 15-year-career, Greinke has played for five different teams. A sixth could soon be added to the list, though a reunion with a former club could also be in the cards.