The Diamondbacks have reinstated experienced starters Merrill Kelly from the 60-day injured list, the team announced. To make room for the right-hander in the active roster, the right-handed reliever Scott McGough was sent to Triple-A Reno. In the meantime Humberto Castellanos was designated for deployment to free up a place in the 40-man squad.

Kelly, now 35, was a durable and reliable starter for the Diamondbacks from 2021-23, making 90 starts and pitching to a 3.66 ERA and 4.16 SIERA. He got off to a strong start in his first four appearances in 2024, posting a 2.19 ERA and 3.88 SIERA in 24 2/3 innings pitched, but suffered a strained teres major muscle in mid-April. The right-hander will make his highly anticipated comeback this afternoon against the Phillies, and the D-backs will have their entire rotation healthy for the first time this season. Manager Torey Lovullo now has six healthy starters at his disposal: Zac Gallen, Brandon Pfaadt, Eduardo Rodriguez, Jordan Montgomery, Ryne Nelson and Kelly.

McGough, 34, signed a two-year deal with Arizona in the 2022-23 offseason. He was a serviceable middle reliever last season, posting a 4.73 ERA and a 3.49 SIERA in 70 1/3 innings, but he’s struggled in 2024. In 29 innings, McGough has a 6.83 ERA and a 5.63 SIERA. This is the third time he’s been optioned this season.

As for the 26-year-old Castellanos, he has failed to make much of an impression in 32 games (16 starts) for the Diamondbacks at the major league level. Since the D-backs claimed him off waivers from the Astros in the 2020-21 offseason, he has posted a 5.29 ERA and a 4.89 SIERA in 100 1/3 innings as a starter and reliever. His minor league stats aren’t much better; he has a 4.59 ERA and a 6.64 FIP at Triple-A this year. If Castellanos comes through waivers undeclared, he has the right to decline an outright assignment to Triple-A and opt for free agency.