5) Tommy Edman
Edman made his debut during the 2019 season and replaced a struggling Matt Carpenter at third base. He was immediately impactful and earned the nickname Tommy Two Bags during his strong rookie campaign. The toolsy infielder hit .304 with a .850 OPS in 92 games. He deserved much more attention in the NL Rookie of the Year voting than he received. 2019 was easily Edman's best year with the Cardinals, and he hasn't reached the .300 mark in another season with St. Louis but has proven to be an elite defender at six positions, including shortstop and center field. This, along with his elite baserunning, has made Edman a productive regular over the last few seasons. Edman's time in St. Louis will be remembered fondly.
Edman rounds out our list, though there are other more obvious answers that could have filled this spot. these include Jim Edmonds, who hit .300 three times as a Cardinal, Lance Berkman, who hit .301 for the 2011 squad, and Paul Goldschmidt, who hit .317 during his 2022 NL MVP campaign. Instead, I selected Edman, and that's because the 2019 Cardinals featured five .300 hitters, four of which qualify as ultimate deep dives.
Deep Dive: As Edman was breaking out in 2019, four other Cardinals were busy putting together .300 seasons of their own. However, these weren't the usual suspects. None could be considered regulars or even established offensive players. They were role players, and none received more than 44 plate appearances. They were, starting with the lowest average, Randy Arozarena, Lane Thomas, Ryan Helsley, and John Brebbia. Arozarena would be traded just after the season concluded, and Thomas dealt with injuries before being traded to the Nationals in exchange for John Lester at the 2021 trade deadline. In 2019, few imagined that Helsley could eventually become a true lockdown closer.
The last name, John Brebbia, is likely the least recognizable. 2019 represented his third consecutive productive season with the Cardinals, though it would also be his last. Brebbia missed all of 2020 and resurfaced in 2021 as a Giant. After struggling in his first season in San Francisco, Brebbia reclaimed his old form and has been excellent over the previous two seasons. He's definitely somebody the Cardinals wish they'd held on to. In 2019 though, the reliever went one for one, finishing the year with a perfect 1.000 batting average and a 2.000 OPS. It remains the only hit of his career.