Should the St. Louis Cardinals Be Worried About Rosenthal?

Trevor Rosenthal got a rare night of rest Friday, as Pat Neshek closed out the Cardinals victory against the San Diego Padres. Rosenthal closed out his 36th save of the season on Thursday, but he again made it interesting, loading the bases and giving up one run before striking out Tommy Medica to end the game. The 36 saves is by far his career high, but many of them have come in high pressure situations where Rosenthal has put the game in doubt.

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Many are wondering if Matheny is overusing Rosenthal, as he has already accumulated 56 innings this season and is on pace to eclipse his season high of 74 innings, set a season ago. Matheny has continually sent the righty out this season on back-to-back nights and occasionally for three or more straight games. The 56 innings is currently the most among top ten closers in the game.

As the season has continued, Rosenthal’s velocity has continued to drop and his groundball rates and lineball rates have skewed far away from his 2013 totals. His linedrive rate of 28.4% is nearly ten points higher than it was in 2013 and his groundball rate has declined from 44.4% to 38.1% this season. His 3.21 ERA is the second highest of any top ten closer, falling only below Marlins closer Steve Cishek, who owns a 3.86 ERA.

The most damning and concerning statistic for Rosenthal is his BB/9 rate. In 2013, Rosenthal’s control was pin point for a flamethrower, walking just 2.39 batters per nine innings. In 2014, however, that rate has jumped up to 4.82 BB/9, ranking dead last among top ten closers. Craig Kimbrel, arguably the best closer in the game, has the second highest BB/9 rate at 3.94, nearly a full walk less than Rosenthal.

All of the diminishing statistics have lead to Rosenthal’s 1-6 record and four blown saves. Even with his struggles to get through hitless and runnerless innings, Rosenthal has been able to battle through and give up only 3 earned runs in his last sixteen appearances. With Kevin Siegrist’s return from the DL and possible help in the minors from Carlos Martinez, Rosenthal may be given more opportunities to rest and the Cardinals will benefit from it during the latter part of the season.