The Cardinals mostly chose to sit out doing anything last offseason, but they did do one thing. They signed Phil Maton in the middle of spring training to a 1 year, $2 million deal. He pitched well enough that, at the deadline, they received left-handed starting pitching prospect Mason Molina, right-handed reliever Skyler Hales, and international bonus pool money. Honestly, it would have felt like a win in March if they just got the bonus pool money.
Presumably, the Cardinals will try to do something similar this offseason. Sign an ignored relief pitcher for peanuts, hope they pitch about as well as Maton did, and then trade them at the deadline.