A day before Cardinals lefty Kwang Hyun Kim was set to make his fifth start of the year, an injury has paused his season and caused the team to reshuffle its rotation.

The Cardinals placed Kim on the 10-day injured list on Saturday, retroactive to Wednesday.

On Friday morning, Kim experienced abdominal pain on his right side and was sent immediately to the emergency room at a Chicago hospital. He was diagnosed with a kidney ailment and remained in the hospital until Saturday afternoon as the pain subsided. He was placed on blood thinners and prescribed medication. The specific diagnosis was renal infarction, president of baseball operations John Mozeliak said.

Kim is feeling much better now, both Mozeliak and manager Mike Shildt said, and Kim and his interpreter, Craig Choi, will return to St. Louis on Sunday. The Cardinals now will start Dakota Hudson on Sunday and use the bullpen for Game 2 of Saturday’s doubleheader at Wrigley Field.

“The good news is, he is feeling much better and the optimism for him to pitch or the expectation for him to pitch at some point this year is still a real possibility,” Mozeliak said. “I think we’re just going to see what happens over the next week or so and how he responds to his medication, but he’s doing well, he feels good and obviously this is something we can control.”

Kim pitched five scoreless innings on Tuesday against the Reds. Over five appearances (four starts) this season, Kim is 2-0 with a 0.83 ERA and one save over 21 2/3 innings. Kim has a 0.44 ERA over his four starts.

After returning to St. Louis, Kim will be allowed to participate in baseball activities at Busch Stadium. Because he’s on blood thinners -- which help blood flow smoothly through veins and arteries but also cause one to bleed more if cut -- he will have to be careful. He's in a different situation than outfielder Dexter Fowler, who was placed on the injured list because he needs to take medication that could suppress his immune system and make him more at risk for COVID-19.

“What you really don’t want to have happen is obviously any bleeding or any bruising,” Mozeliak said. “What it has to do with is just sort of protecting himself. We want to see how the medication works with him for the next week or so, and then pending on how that goes, we’ll then determine if we could actually use him in a game and how we would do that.”

Mozeliak said this kidney ailment is something Kim has experienced in the past, and the Cardinals were aware of it before signing him this past December. But the pain that occurred Friday was unexpected. When it first began, the Cardinals were concerned it might have been related to the appendix, but no surgery was needed once Kim got to the hospital.

“This has some level of more severity for long term but is also something that’s controllable and manageable that you don’t have to have surgical intervention,” Mozeliak said. “So, to some level, there’s some relief.”

As of Saturday afternoon, Kim is “completely pain free,” Mozeliak said, and the Cardinals feel more optimistic that he will be able to return this season.

“There are small hurdles until we get him back on the field to know if that’s doable,” Mozeliak said. “If you and I were talking yesterday, I would have not had any sense of optimism, but where we are today, we feel really good about what we’ve learned.”

In a corresponding move, the Cardinals activated Andrew Miller (left shoulder soreness) from the 10-day injured list. The Cardinals added right-hander Nabil Crismatt as the 29th man for the doubleheader at Wrigley Field. The Cardinals' pitching plan for this weekend has not gone according to plan, with Jack Flaherty lasting only 2 2/3 innings Friday night and the rotation reshuffling that occurred Saturday.

Shildt said he feels that the seven-inning doubleheader game Saturday night is more manageable for the bullpen to handle rather than a nine-inning game on Sunday. He also is managing with an eye toward next week’s doubleheaders on Tuesday and Thursday.

“It’s not an ideal scenario, in any way shape or form, but we’re fresher now heading into Game 2 in a seven-inning situation with a guy that we feel can give us some length in that nine-inning game in Dakota,” Shildt said. “And then have some guys be able to have some rest beyond that for the doubleheader on Tuesday.”

Childhood Cancer Awareness Day
For the fifth consecutive year, MLB and its clubs raised awareness for childhood cancer during all games on Saturday for a special league-wide day in home ballparks. MLB’s “Childhood Cancer Awareness Day,” held during Childhood Cancer Awareness Month in collaboration with Stand Up To Cancer (SU2C), combined a visual and ceremonial demonstration of support for the cause with outreach to local hospitals treating young patients in their communities. Childhood cancer is the leading cause of death by disease among children in the United States and Canada.

The Cardinals joined all on-field personnel, including players, coaches and umpires around baseball in wearing gold ribbon decals and wristbands during Saturday's doubleheader against the Cubs.

Clubs also featured ceremonial activities in ballparks. Club activities included pregame ceremonies, cardboard cutouts of pediatric patients in stands at ballparks, virtual patient first pitches, virtual player hospital visits and more.

Childhood cancer awareness efforts in previous seasons have included special pediatric cancer awareness batting-practice T-shirts, online campaigns to empower fans to hold fundraisers for pediatric cancer research and donations to local children’s hospitals. MLB and its clubs have supported the fight against cancer through a variety of initiatives for many years. As Stand Up To Cancer’s founding donor, Major League Baseball has pledged more than $50 million to SU2C’s collaborative cancer research programs, providing invaluable support. Launched in 2013, the work of the Stand Up To Cancer/St. Baldrick’s Foundation Pediatric Cancer Dream Team has helped to develop new immunotherapy approaches and contributed to the development of two new treatments for difficult-to-treat pediatric leukemias that have been approved by the FDA. MLB has recognized SU2C at its jewel events since the '09 World Series.