Andre Pallante
Andre Pallante has always gotten by on his reverse splits, as a right-handed pitcher who excels at retiring left-handed hitters, but his ability to get right-handed hitters out has diminished precipitously this season. Right-handers are hitting .355 off of Pallante, although his BABIP of .313 is the same as last year's.
Pallante is one of the best ground-ball pitchers in the sport, but even his 77.7% ground-ball rate hasn't been able to help him as much as it would in years past given the elimination of the defensive shift. Further hurting Pallante is his increased walk rate, from 8.8% of batters last season to 10% this year.
Opposing hitters have teed off on Pallante's breaking pitches, batting .326 on his slider and .321 on his curveball. The slider's effectiveness has declined dramatically, as opponents hit only .195 off of it last season.
Pallante's bullpen spot could be in jeopardy next season given the Cardinals' desire to catch up with the times and find pitchers with swing-and-miss stuff, which Pallante decidedly lacks. On the other hand, pitchers who can retire lefties are valuable, so the Cardinals might give him one more chance.