This might seem an unorthodox signing, but the team could really benefit from the signing of Chris Davis. The team has Matt Adams at first base currently, but he continues to be the victim of injury and perhaps the team would consider moving him for pitching and signing Davis. Adams has missed a lot of time and at the age of 27, he is hardly a young prospect anymore.
Davis has ridiculous power and would evoke memories of Mark McGwire to Cardinals fans. He slugged 47 home runs last year while driving in 117 runs with a .262 batting average. Davis strikes out a lot, but also walks a ton. He recorded a .361 on base percentage last year and has a .330 career on base percentage. He also has the ability to play the outfield, although he is clearly a better defender at first base.
Signing Chris Davis would not be cheap. He is 29 years old and is sure to have some more pop left in the bat. Davis will be highly sought after and there are many rumors linking him to multiple teams within the Major League community. If the Cardinals want to be players in signing him, they would need to be aggressive but Davis could put up huge numbers in St. Louis for years to come.