#2 - Nolan Arenado
Like Paul Goldschmidt, Nolan Arenado just wasn't himself in 2023. He regressed from a 151 OPS+ to a 109 last season. Due to injury concerns and frustrations with the team's performance, Arenado was only able to perform well for flashes in 2023. It was good enough to lead to an 8th consecutive All-Star selection, but his numbers fell off immediately after the break. What's more concerning is that Arenado's defensive numbers dropped uncharacteristically. For stretches in the first half, he was below league average, and for the first time in his 11-year career, he failed to win the Gold Glove at third base.
Unlike first base, the Cardinals have very few quality options to fill in for Arenado at third base should he suffer another injury. Nolan Gorman is much more comfortable at second, and Jordan Walker is fully converted to an outfielder so that only leaves a combination of Donovan and Edman, neither of which can play the same premium defense Arenado does.
With Arenado's defense lacking in 2023, the Cardinals' defense was also subpar. Having a bounce back in 2024 is critical for both the lineup and the defense to return to their old ways. Simply put, Arenado is the most indispensable member of the Cardinals' lineup and they will need him at his best to contend for a championship this year.
Arenado is also a few years younger than Paul Goldschmidt, so the Cardinals are still hoping to get a few more prime years from him as the highest-paid player on the roster. A 109 OPS+, just 9% above league average, won't cut it in 2024 and he knows that more than anyone. He's as hungry as ever to rebound next year on both sides of the ball and knows a repeat of 2023 is just unacceptable.