ST. LOUIS -- Kwang Hyun Kim’s return has been marked down in pen.

The left-hander will make his awaited return to action and his 2021 debut when the Cardinals take on the Phillies on Saturday in Philadelphia, manager Mike Shildt said prior to Tuesday’s tilt against the Nationals. The Cards hope the addition of a key contributor from last season will help a scuffling rotation.

As part of slotting Kim into the rotation, Daniel Ponce de Leon has been moved to the bullpen as a long-relief option after going just 1 1/3 innings in his last start on Sunday; John Gant will remain the No. 5 starter.

For Kim, Saturday will mark the beginning of his sophomore MLB season, and he’ll be healthy after he went down with back tightness in a bullpen session following a Grapefruit League game on March 8. The left-hander struggled early in Spring Training, failing to make it out of the first inning in each of his first two starts and then making one tune-up appearance on March 27.

Since then, the Cardinals have remained cautious with the 32-year-old, who signed with the club prior to the 2020 season on a two-year, $8 million deal after 12 years spent pitching for SK Wyverns in Korea. Kim was dynamite last season, opening the year as the closer and then entrenching himself in the rotation with a 1.62 ERA across eight games (seven starts).

Since the outset of April, Kim has built back up via simulated game sessions, facing Cardinals hitters at the alternate training site in Sauget, Ill., with the last one coming this past Sunday.

Each outing has needed to check a box, with one of the final checkmarks being Kim’s aptness as a batter and baserunner, the latter of which he worked on at Busch Stadium on Tuesday. With the DH in play last season, Kim has only three professional plate appearances on his resume, the last of which came in 2010 in Korea.

Oviedo down, Whitley up
The Cardinals had two reasons for recalling Kodi Whitley and optioning Johan Ovideo prior to Tuesday’s game against the Nationals.

The first is a need for bullpen arms, with the Cards being only one of two teams in the Majors this season to have called upon their ‘pen for more innings than their starters.

The second is that the club is approaching a stretch of 17 consecutive games without an off-day beginning on April 23. Intending to “honor the off-days” and keep starters on regular rest, St. Louis will need a sixth arm to make spot starts during the marathon stretch. Oviedo will be that arm, and he’ll be able to stay on that track at the alternate training site.

Whitley, one of the surprise absences from the Opening Day roster, is set for his 2021 debut in the interim after impressing as a rookie last season and then not allowing a run over 7 1/3 Spring Training innings.

“When you’re a young guy, it happens,” said Whitley, 26. “You can’t get down on yourself for being optioned. A lot of times when you get optioned, it’s not a performance thing. … Whenever you get sent down, just stay sharp. You don’t hang your head because you got sent down. You stay sharp for the next call.”

Shildt embarks on a milestone …
Tuesday marks Shildt’s 300th game as Cardinals manager, another milestone in a career highlighted by progression. Never a Major nor Minor Leaguer himself, Shildt was named interim manager after the departure of Mike Matheny in the 2018 season and then given the permanent position shortly thereafter. Shildt’s teams are 167-132 entering Tuesday, with postseason appearances in each of his full seasons at the helm.

“I'm a big believer in growth and continual improvement,” Shildt said. “ ... The fact of the matter is I did have a lot of experience managing, but clearly not at the big league level. I think there’s no question there’s been some bits of growth. There's been more consistent building of relationships, more familiarity with the league, more familiarity with just what it takes to do this job, what the asks are, on the field during the day, off the field. All the many different things that come into the wonderful job of the St. Louis Cardinals manager.

“I had no idea today was the 300th game.”

… and one soon for Yadi
Yadier Molina was kept out of the starting lineup for the first time this season on Tuesday in what would have been his 2,000th career game behind the plate. Six catchers have reached that number in MLB history; none has done so with one team.

Molina is slated to become the first to do so when he catches longtime batterymate Adam Wainwright in Wednesday’s matinee and series finale.