5. Shop Ryan Helsley and Giovanny Gallegos, take an offer if a team is willing to part with significant assets
This is not essential to pull off at the deadline, but July tends to be the time that relievers have their highest trade value. The Cardinals should make it known that they are open to offers on their top relievers, and are willing to make a move for the right price.
Both Helsley and Gallegos are regarded as two of the best relievers in baseball, and both have multiple years of control remaining. This will be especially appealing to teams, as they don't have to pawn off assets for just a few months of the reliever. They can add a Helsley or Gallegos knowing they will be with their club beyond 2023.
Why would the Cardinals do that if their bullpen is already so thin? Relievers are so volatile and at any moment, Helsley or Gallegos could drop off significantly. When your club is not in contention, it's better to capitalize on the value of your relievers than to hold onto them.
The right deal has to be there though. There is no point in dealing either of them off unless they can a strong offer. Otherwise, they can wait for the offseason or have them on their 2024 roster.