St. Louis Cardinals: Five story lines for the Cardinals in the weeks ahead

2) Trevor Rosenthal could replace Seung-hwan Oh as the St. Louis cardinals closer

Almost a complete flip flop of last year, 2017 has Trevor Rosenthal looking like the more dominant pitcher compared to this year’s ineffective Seung-hwan Oh.

In 17.1 innings, Rosenthal carries a 2.60 ERA, 1.13 WHIP, and twenty-nine strikeouts (15.1 K/9) compared to twenty-three innings for Oh posting a 3.13 ERA, 1.435 WHIP, and twenty strikeouts (7.8 K/9). Oh has given up twenty-three hits in twenty-three innings to go along with ten walks. The command for him isn’t there this year and he’s not generating as many swing and misses.

Digging deeper, Fangraphs  shows that hitters are seeing the ball better against Oh and are capitalizing on pitches in the zone. Last year Oh generated 18% swing and misses on strikes, which was well above the league average, whereas this year he has regressed to only 12.7% swing and misses on strikes. The dominance isn’t there, and it’s time for Rosenthal to regain his closer status.

On the flip side, the velocity for Rosenthal has returned and his control has been near razor-sharp. The 2015 Rosenthal has come out of hibernation, posting the highest K% in his career at 43.3%, (yes he is almost striking out half of the batters he faces). Rosenthal has been untouchable at times this season.

Fourth all-time in St. Louis Cardinals saves with 113, it’s time for Rosenthal to take over the ninth inning responsibilities due to Oh’s inability to close out games effectively. This move would also free up Oh to pitch more than one inning, which both he and Matheny tend to like.