After a stretch as one of the St. Louis Cardinals’ most dynamic outfield prospects in recent memory, switch hitter Dylan Carlson was traded to the Tampa Bay Rays at Tuesday’s trade deadline. St. Louis received right-handed reliever Shawn Armstrong in return.

Armstrong, 33, is 2-2 with a 5.40 ERA for the Rays this season. He recorded a 1.38 ERA for Tampa in 2023, and has maintained a strikeout rate near 10 per nine innings. His fielding independent pitching mark is at 3.76, suggesting he has pitched to a degree of unfortunate results.

“I just think he can fit into our bullpen,” president of baseball operations John Mozeliak said. “Adds some real depth from the right side, and higher leverage situations he can see. As you can see, over the last month or so, (Andrew) Kittredge and (Ryan) Fernandez are having to get a lot of that, and we just wanted someone to help with that.”

Carlson, 25, was drafted in the first round of the 2016 draft and quickly became the team’s top prospect. He made his Major League debut under strange circumstances during the pandemic-shorted 2020 season, receiving his first call up in the wake of the team’s major COVID-19 outbreak which derailed the season for two weeks and left them desperately short of players.

“Obviously it’s a little bittersweet when you have to trade somebody like a Dylan Carlson, but in all honesty, it just wasn’t working here,” Mozeliak said. “We were going to be left with a tough decision on what to do, and so ultimately, we felt like, give him a change of scenery, be able to address some of our needs.”

“That’s not something that’s up to me,” Carlson said Tuesday when asked about the possibility of being traded. “For me, all I can do is show the energy and effort I give whenever I get an opportunity to go out there and play. I don’t control what uniform they make me put on.”

In making the trade to remove Carlson from the active roster, the Cardinals were able to officially activate Tommy Pham, acquired Monday from the Chicago White Sox.

Carlson seemingly broke out in 2021, finishing third in NL Rookie of the Year voting while hitting 18 home runs and posting a .780 OPS. That season, though, is the only one of his career to date in which he has been even a league average hitter. Injuries and poor performance combined to shunt him into largely a reserve role in which he struggled to find traction.

After a solid spring training this year, though, he was primed to open the season as the team’s starting center fielder thanks to Tommy Edman’s slow recovery from wrist surgery.

On the eve of the season, however, he suffered a serious shoulder injury in an outfield collision with Jordan Walker. That was not only a direct setback, but Carlson also described an inability to keep up with his rehab from ankle surgery which cut his 2023 season short.

This season, he’s hitting just .198 with a .515 OPS and no home runs in 138 plate appearances. His defense has also suffered; two crucial misplays on Friday night against the Washington Nationals cost the Cardinals as many as five runs in an eventual two-run loss.

Seemingly primed to assume at least platoon duties in center with Michael Siani, Carlson instead found himself without an obvious roster fit. Monday’s acquisition of Pham – a right-handed outfielder who can play all three positions and punishes lefties – made Carlson the clear odd man out.

“I just feel like his timing never got going, so hopefully he can reestablish himself,” Mozeliak said of Carlson’s season. “I certainly think he’s a talented guy, but I do think his time here, it wasn’t fair to him, and it wasn’t helping us.”

Armstrong joins Pham and right-handed starter Erick Fedde as the team’s deadline additions, fulfilling each of their most obvious needs.

Fedde will make his Cardinals debut on Friday against the Chicago Cubs at Wrigley Field.

Mozeliak added that his “hands were not tied” financially by ownership in the runup to the deadline, and claimed that the Cardinals took on roughly $1.5 million in salary commitments, which was able to be independently verified using publicly available data provided by FanGraphs.

That amount also doesn’t include the money still owed – roughly $2.5 million – to reliever Giovanny Gallegos. The Cardinals were not able to trade Gallegos before the deadline and he will be passed through irrevocable waivers starting Wednesday. If he clears, he will be able to sign with any team, and the acquiring team will only be responsible for paying him the prorated league minimum salary.

St. Louis enters play Tuesday seven games back of the lead in the NL Central and two games off the pace of the third NL Wild Card. Manager Oli Marmol reaffirmed Tuesday that the club’s goal is to win the division, and a race down the stretch to enter the postseason will test whether the additions made in recent days were sufficient to achieve that goal.

“We think these additions will certainly make us better,” Mozeliak said. “Now we’ll play baseball. Doesn’t matter what I think, right? Go out and prove it.”