Texas pitcher Merrill Kelly will take the mound against his former team for the first time when the Rangers clash with the Arizona Diamondbacks on Wednesday afternoon in the finale of a three-game interleague set in Arlington, Texas.

The Diamondbacks will send right hander Zac Gallen (9-12, 5.31 ERA) to the hill to oppose fellow right-hander Kelly (9-7. 3.38), whom the Rangers acquired at the trade deadline.

The teams have split the first two games of the series, with Texas winning in 10 innings on Monday and the Diamondbacks responding with a 3-2 victory on Tuesday that was delivered by a game-deciding, ninth-inning home run by Ketel Marte.

Kelly, who was a stalwart of the Diamondbacks' pitching staff from 2019 until the trade on July 31, has made two starts for Texas. He is 0-1 in those two appearances while amassing a 5.40 ERA over 10 innings, allowing two runs on four hits in 5 2/3 innings in a no-decision at Seattle on Aug. 2 before surrendering four runs on five hits and a season-high five walks over 4 1/3 innings Friday in a loss at home to the Phillies.

It was the first time Kelly has walked five batters in a game since 2023.

"I knew I could only walk a tightrope so long by putting that many people on base, giving that many free passes," Kelly said after the setback against Philadelphia. "Eventually, it ended up coming back to bite me.

"It was probably a mix of just overcorrecting things," Kelly said about his wildness. "I would kind of fly open, let a ball run too far arm-side and then try to overcorrect it, and then I would kind of pull it and yank it glove-side. Just kind of in-between on everything."

Since Kelly had spent his entire career as a member of the Diamondbacks until two weeks ago, he has never pitched a game against his previous team.

"We faced him a couple times in live (batting practice)," Arizona shortstop Geraldo Perdomo said. "We're gonna be ready for Merrill."

Gallen has suffered through a sub-par campaign and is staring at his first losing season since going 4-10 in 2021. He produced a record of 43-19 from 2022-24 and was finished in the top five in National League Cy Young Award voting in both 2022 and 2023.

Gallen has been better in his last two starts, winning twice and sporting a 2.25 ERA over 12 innings this month. His most recent outing was a six-inning stint at home against Colorado on Friday in which he gave up one run on four hits and three walks while striking out six. Gallen is 4-3 in seven appearances since July 1.

He is looking forward to matching up against Kelly, his former running buddy.

"It'll be fun," Gallen said. "I mean, I know as a pitcher, you're more thinking about the lineup you're facing. I'm wondering how weird it'll be for our hitters to face Merrill. For us squaring off against each other, I don't think of it as much in that sense. But still, it will be fun, nonetheless."

Gallen is 2-1 with a 2.78 ERA in four career starts against the Rangers covering 22 2/3 innings. He won his last time out versus Texas, hurling five scoreless, two-hit innings in a game the Diamondbacks took 6-0 on Sept. 10 of last season in Phoenix.