Bailey Ober's second-half slump has cost him his spot in the Twins' rotation and on the roster.

Ober, who has added more than a run to his season ERA in eight post-All-Star starts, was optioned to Class AAA St. Paul on Monday, the Twins announced. Dallas Keuchel, who has not allowed a run over his past 11 innings, figures to inherit Ober's turn in the rotation.

Lefthander Kody Funderburk, a 15th-round draft pick in 2018 who started the season at Class AA Wichita, has been called up in Ober's place, giving the Twins eight relievers in the bullpen once more. Funderburk has struck out 75 batters in 52 innings for the Saints this season, posting a 2.60 ERA with five saves.

Ober, who was crowded out of the Twins' rotation out of spring training until Tyler Mahle suffered a season-ending injury. seemingly had established himself as a fixture in the Twins' rotation with a strong first half. The 28-year-old righthander gave up no more than one run in four of his first five starts, and the Twins won four of them. He reached the All-Star break with a 2.61 ERA in 14 starts.

But the righthander became home run-prone when the season resumed and had allowed at least one a home run in each of his eight post-All-Star starts. With 140⅓ innings pitched at two levels this season, Ober has far exceeded the 72⅔ he pitched in 2022, and his career-high of 108⅓ innings in 2021, leading to speculation the extra workload was wearing him down.

Ober, though, insisted he hasn't felt any physical affects of the increased workload, saying after his start last Tuesday in Milwaukee: "They have not communicated that [concern] to me. I feel really good. I might have [just] hit my season high in velocity. … I'm trying to help this team win games so we can make the playoffs and make a deep postseason run."

The addition of Keuchel, a former Cy Young Award winner attempting a comeback at age 35, however, has given the Twins a chance to limit Ober's innings and reconsider whether he has a potential role in the postseason. Ober gave up five runs, including a grand slam, in four innings Sunday against the Texas Rangers, but Keuchel pitched five shutout innings in relief, allowing the Twins to rally to a 7-6 extra-inning victory.

Meanwhile, Funderburk has put together a strong season in the Twins organization, holding batters to a .191 average, and righthanders to only .184. Funderburk has allowed only one home run all season, and he has given up only four runs in his past 24 innings. He made his major league debut Monday, pitching a hitless two innings with three strikeouts.

Funderburk's presence give the Twins two lefthanded options out of the bullpen, along with veteran Caleb Thielbar.

To make room on the 40-man roster, the Twins put righthander Oliver Ortega, out because of a back injury, on the 60-day injured list, effectively ending his season.