PHOENIX — The Padres have decided when they will deploy their two new weapons.

Casey Mize will start Wednesday against the Diamondbacks, and Robbie Ray will start Friday when the Padres return home to play the Astros.

Ray is expected to join the team here Tuesday night or Wednesday after attending to his family and their move following his trade from the Giants.

Mize and utility player Gage Workman, acquired in the same trade from the Tigers on Monday, were activated before the game.

“I’m ready,” Mize said. “It’s been a little bit, so I’m ready to get out there.”

Mize was withheld from his scheduled start last Friday, as the Tigers decided to protect against the possibility of injury before they could trade him.

He joins the Padres having posted a 2.20 ERA over his past five starts (28 ⅔ innings). His 2.70 ERA in 16 starts this season ranked fifth among American League starters with at least 80 innings pitched. He missed time twice this season while on the injured list with an adductor (groin) strain in May and again in June.

Ray’s 1.09 ERA over his past eight games (seven starts) is tied for best in the major leagues in that span. The 34-year-old left-hander has a 3.08 ERA in 22 starts overall.

The two new starters’ merely joining the Padres provides an upgrade in that it essentially doubles the size of the rotation. The Padres have for almost two weeks gone with Michael King and Walker Buehler as their only starting pitchers given a normal runway to go as long as they could or at least not be pulled unless the score and situation dictated it. The other three turns in the rotation had been a somewhat choreographed mismash of pitchers each day.

But Ray and Mize are not just arms. They are expected to continue to excel and greatly improve what the Padres are consistently getting at the start of games.

Ray has nine quality starts this season and has twice gone eight innings in a game. Half of Mize’s 16 starts have been quality starts, and he threw seven scoreless innings at Yankee Stadium on June 29.

King has 10 of the Padres’ 18 quality starts this season. King (twice) and Randy Vásquez are the only Padres starters to work seven innings. No Padres starter had gone further than that in a game this season.

“It should compete with anybody,” King said of the rotation. “… I think that both of them are going to be huge for us down the stretch.”

Getting to work

Mize found out he had been traded a few minutes before the 3 p.m. PT deadline.

Workman did not learn of his inclusion in the deal until a little while after 3 o’clock.

“I thought the deadline was over,” he said. “It was a surprise to me.”

Workman played 16 games for the Tigers this season and three with the White Sox and nine with the Cubs in 2025. But he was with Triple-A Toledo before being acquired by the Padres.

Now he is in the major leagues, where he can fill in all over the infield and at the corner outfield positions.

“He’s got a ton of defensive versatility,” Stammen said. “But probably most important is his left-handed bat.”

Workman was 6-for-38 with three doubles and two home runs for the Tigers this season. He is hitting .167/.183/.352 in 55 career major league plate appearances.

“I think it’s kind of exciting,” he said, “getting new eyes on you and see what they see.”

Moves

To make room on the active roster for Mize and Workman, the Padres optioned pitcher JP Sears and catcher Rodolfo Durán.

Sears had a 4.68 ERA in eight games (six starts) since being called up in June. He pitched an inning in relief on Sunday, three days after throwing 67 pitches in 2⅔ innings.

He was the logical pitcher to send down, as he could be optioned. The only other pitchers on the roster who can be optioned are relievers Jeremiah Estrada and Bradgley Rodroguez, who are crucial back-end options in the bullpen.

Durán hit .146 with four doubles and two home runs in what turned out to be an extended run in his first major league stint after 11 years in the minor leagues. Initially called up in early May when Luis Campusano went on the injured list, Durán had been the Padres’ third catcher since Freddy Fermin returned from the IL on July 17.

Another pitcher will have to be removed from the 26-man roster when Ray is added. That will almost certainly involve an injured list move or someone being designated for assignment.