DENVER (Interstat) — The Arizona Diamondbacks visit the Colorado Rockies on Friday, May 15, 2026, at Coors Field in the opener of a three-game series. First pitch is scheduled for 6:40 p.m. MDT.

Arizona (20-22) will start right-hander Merrill Kelly (2-3) against a Rockies starter yet to be announced. Kelly enters the game with an ERA hovering near 4.50 after a rough May, but Arizona’s bullpen has shown signs of stabilization of late.

Colorado (17-27) has lost six of its last nine games and sits in last place in the National League West. The Rockies’ offense has struggled to produce consistently, averaging fewer than four runs per game over the past week.

Arizona player to watch: Ryne Nelson. The right-hander, working out of the bullpen, has been effective in his past three appearances despite taking losses in each. On May 13 against Texas, he threw 7 innings, allowing 4 hits and 3 earned runs with 8 strikeouts. Over his previous two outings, Nelson yielded a combined 2 earned runs across 12 1/3 innings with 11 strikeouts. He has been Arizona’s most reliable arm out of the bullpen since a disastrous April 19 outing against Toronto in which he allowed 8 hits and 8 earned runs in one-third of an inning.

Colorado player to watch: Tanner Gordon. The left-hander has been used mostly in relief but has shown improved command. On May 14 against Pittsburgh, Gordon threw 4 innings, allowing 3 hits and 1 earned run with 5 strikeouts. Over his past five appearances, he has a 2.70 ERA and 21 strikeouts in 17 innings. However, he has been prone to the long ball, having allowed 4 home runs in that span.

The Interstat game simulator projects a 4-3 Arizona win. Arizona is a -1.5 run favorite, and the over/under is set at 11.5 runs, reflecting Coors Field’s hitter-friendly environment.

Arizona lost 5-6 to Texas on Wednesday, May 13, despite Nelson’s strong outing and a 2-RBI performance from Nolan Arenado. Colorado lost 2-7 to Pittsburgh on Thursday, May 14.

The series continues Saturday and Sunday before Arizona returns home to face San Francisco. Colorado hosts Texas next week before traveling to Arizona for a four-game set starting May 21.