The addition of Andrew Kittredge to the bullpen gives the St. Louis Cardinals an experienced and talented back-end reliever. He provides Oliver Marmol another option late in games, and he makes the team that much better for next year.
However, Kittredge alone likely isn't enough. Katie Woo had a mailbag the other day (subscription required); in her mailbag, she began the discussion by bringing to light the Cardinals' plan for pitching this offseason. John Mozeliak's goal of adding "at least two bullpen arms" isn't accomplished just yet unless he considers one of Wilking Rodriguez, Ryan Fernandez, or Nick Robertson sufficient, which he hopefully doesn't.
Woo stated that there is still room in the budget, despite it possibly being capped out, for one more reliever. This pitcher likely won't come from the Josh Hader bucket, and it's also unlikely he comes from the Jordan Hicks/Hector Neris bucket. Instead, Katie gave a very specific dollar amount for this final reliever.
"The Cardinals are looking to add one more reliever with an AAV ranging around $5 million, per an industry source. Pitchers such as Matt Moore and Phil Maton fit that targeted range and the Cardinals have been linked to Maton throughout the winter. The club is high on its bullpen but is still hoping to add one more reliever."- Katie Woo
$5 million isn't much in today's free agent market. Given the rise in prices for pitchers of all varieties, Bill DeWitt and Co. are really limiting what John Mozeliak can do with his final signing. Most of the high-end, younger relievers exceed that price tag.
Woo does state two specific relievers that have been reported as options in the past by Derrick Goold of the Post Dispatch and others in Phil Maton and Matt Moore. I also discussed Moore in a piece back in October as a player St. Louis should target. I also brought up names like Matt Barnes, Joe Jimenez, and Keynan Middleton as options, but Matt Barnes is likely the only pitcher of that bunch who will be affordable given these financial constraints.