ST. LOUIS -- A flurry of moves greeted the Cardinals in their return to Busch Stadium for Tuesday's seven-inning doubleheader against the Twins, including activating Game 1 starter Carlos Martínez from the injured list and optioning their top prospect, outfielder Dylan Carlson, to the alternate training site in Springfield, Mo.

"He came up, had a lot of quality at-bats, lot of proverbial tough luck, lot of lineouts, lot of live drives that found gloves in the outfield," manager Mike Shildt said of the 21-year-old Carlson. "The league adjusted and started treated him like he was a 15-year All-Star and pitched him tougher than anybody in the league. Lot of soft stuff, and he just started to expand a little bit.

"It's a chance for him to refocus a little bit, go down and get some at-bats in a more controlled setting."

To make room on the 40-man roster for Martínez, who is returning from a positive COVID-19 test, the Cardinals designated right-hander Ryan Meisinger for assignment. The 26-year-old will go through waivers, and if the 29 other teams don't claim him, he could end up back with the Cards and even in their 60-man player pool.

Right-hander Daniel Ponce de Leon was activated as the 29th man for the twin bill and is expected to start the second game of the doubleheader. Ponce de Leon has spent the past 10 days in Springfield, where he has maintained his arm strength and reconnected with the strike zone after his recent starts were undone by walks and long at-bats.

With Dexter Fowler on the injured list, the Cardinals' outfield is now left fielder Tyler O'Neill, center fielder Harrison Bader and right fielder Lane Thomas, who can also play left and center. Tommy Edman could be classified as the fourth outfielder as he rotates between the infield and outfield. He played third base for the first game Tuesday.

O'Neill, Bader and Thomas were batting seventh, eighth and ninth, respectively, in the first game Tuesday. Those three outfielders entered Tuesday hitting a combined .198 with 46 strikeouts in 65 games, but the Cardinals have liked their recent at-bats, especially this weekend against the Cubs. Carlson was out of the lineup the past three games and wasn't going to get much more playing time, Shildt said.

"He's not going to get at-bats, and it's going to be harder to stay sharp mentally and physically," Shildt said. "So he'll go down, reset and be ready."

Carlson didn't fare well in his first stretch of Major League action. The rookie hit .162 (12-for-74) with five walks and one home run for a .458 OPS. He struggled particularly with runners in scoring position, hitting .125 (3-for-24). The way Carlson was pitched was not typical of a rookie; instead of hurling fastballs at him, pitchers tested him with their offspeed stuff. He struck out 23 times, and when he did hit, the balls were hard-hit -- right into defensive positioning.

Now Carlson will return to Springfield, stay as sharp as he can with the setting there -- facing live pitching from the club's top pitching prospects -- and be ready to potentially return to St. Louis before the regular season ends later this month.

"He did play good defense when he was here, he did have some good at-bats, he just got in a stretch where the at-bats weren't there as much and they weren't as consistent as he and we would like," Shildt said. "But he's a good player. He's going to be a really good player. This is not an uncommon and unprecedented thing. It's not Dylan in a silo. It's the other guys stepping up as well."

Cardinals pay tribute to Brock
The streets around Busch Stadium were quiet Tuesday morning, but baseball fans had streamed in over the past two days to pay tribute to one of the greatest Cardinals of all-time.

Lou Brock's statue outside of the stadium was decorated with trinkets, flowers and sweet messages for Sweet Lou, who died Sunday afternoon at 81 years old.

The Cardinals etched a number 20 onto the infield on Tuesday -- right next to the base that Brock stole so often.

Updates on Kim, Fowler
Lefty Kwang-Hyun Kim threw on Monday and Tuesday at Busch Stadium and continues to feel better after a kidney ailment put him in the hospital for a day in Chicago and on the 10-day injured list. Shildt said Kim has appointments with the medical staff the next couple mornings, and within the next couple of days, the Cardinals hope he can throw a bullpen session.

"Every day he gets a little stronger, builds back up and has energy and has ability to take that next step," Shildt said. "[We will] continue to evaluate him and make sure he can progress and everything's in the right spot. But so far so good."

The same goes for Fowler, who is on the injured list while he takes medication that could compromise his immune system. Shildt said Fowler is adjusting to the medication and can eat a little more regularly than he was before with his stomach issue.

"It's going to be some period of time," Shildt said, "but he's starting to regulate and feeling better and eat a little bit more consistently. So positive things for him personally."