Jon Morosi of MLB Network reported the news Saturday.
Ray, 27, is 9-6 with a 3.95 ERA and a 1.31 WHIP through 22 starts. He's considered one of the top pitching targets on the trade market as the Diamondbacks prepare to sell at the deadline.
Morosi reported every major name on the Arizona roster is available, with the team looking to build around its farm system.
Ray is one of the best power arms in baseball, striking out 162 batters in 123 innings this season. His 11.85 strikeouts per nine innings ranks sixth among qualifying pitchers with at least 100 innings.
"No, I mean, I'm taking it five days at a time," Ray told reporters of the trade rumors after his last start Monday. "I'm preparing for every start like we're making a push. Whatever happens is going to happen but I'm going to keep preparing for that fifth day."
Ray has spent the last five seasons in Arizona after beginning his big league career in Detroit. He earned All-Star honors in 2017 and has been healthy this season after an injury-plagued 2018.