3. Dylan Carlson
While it is tempting to overreact to his rough stretches since the trade deadline, Dylan Carlson still provides a ceiling of an elite defensive center fielder who can get on base at a high clip with good slugging. Those players are few and far between in the major leagues.
The biggest thing holding Carlson back right now is his ability to hit right-handed pitching. Against right-handers this year, the 23-year old is slashing .210/.290/.343 in 307 PA. For his big league career, Carlson is slashing .227/.306/.383 in 893 PA, a very large sample size to say this is a hole in his game.
On the flip side, Carlson destroys left-handed pitching, slashing .326/.385/.508 in 271 PA in his career. If Carlson could be 60-70% the hitter against right-handers that he is against southpaws, the switch-hitter would quickly become one of the best outfielders in the game.
Even if he never really figures it out against right-handed pitching, his elite defense mixes with his slash line against lefties gives him a pretty high floor in the big leagues. With the promise of Carlson, one would expect he at least becomes competent against righties, which will be important if he wants to have consistent playing time. The Cardinals wealth of options at the position puts the pressure on Carlson to turn things around quickly.