Should we be worried about Seung Hwan Oh’s workload?

In a season filled with perpetual ups and downs, there has been at least one player who has held steady for the St. Louis Cardinals, from a health and performance perspective, since game number one way back on April 3rd against the Pittsburgh Pirates. This player can be described as the rock (or should I say “stone”) of a pretty solid, but not without a lot of moving parts, bullpen — available to pitch seemingly every single day in virtually any role assigned to him by his manager.

This stone (Buddha) is more commonly known as Seung Hwan Oh, a 34-year-old rookie, who has been one of MLB’s best relief pitchers in 2016 — posting an fWAR of 2.2, good for third most valuable in all of baseball, alongside the flame-throwing Aroldis Chapman (2.2) and one notch ahead of Andrew Miller (2.1). Yet, it must be noted that while these three relievers share a nearly identical fWAR, they’ve each taken a very different path to the value they’ve provided to their respective ball clubs.

Oh (62 G) has appeared in 16 more games than Chapman and 9 more games than Miller. Further, Oh (65.1 IP) has pitched 21.1 more innings than Chapman and 9.1 more than Miller. Sure, Chapman’s 30-game suspension to open the season plays a role in the disparity here, but at the same time, it cannot be denied just how much Oh has been used this season. In fact, only four MLB relievers have more innings logged than Oh this season — Joe Blanton (65.2 IP), Carlos Villanueva (67.0 IP), Brad Hand (69.1 IP), and Erasmo Ramirez (70.1 IP) — and each one of them shares the commonality of being a former starting pitcher.

With all of this in mind, should the Cardinals be worried about Oh wearing down by the end of the regular season? With Trevor Rosenthal not throwing a single pitch since July 24th (and not being effective when he was available), a fresh Oh is of utmost importance should the Cardinals be forced into the one-game Wild Card playoff. And let’s be honest, being 13.5 games from the Cubs with only 37 to play, the one-game playoff is the only realistic playoff entry for the Cardinals at this point.

Fortunately, the Cardinals have a few things going for them regarding Oh. First, before the All-Star break, Oh was used in 45 of the team’s 88 games (56.25%). Since the break, Oh has appeared in 17 of the team’s 37 games (45.95%). Thanks to significant run differentials (both positively and negatively), Oh’s usage rate has declined significantly. Plus, it probably helps that he carries the title of “closer” now instead of being the “super reliever” he was earlier in the season. Sure, there are high-leverage scenarios before the ninth inning in which I believe the team’s best reliever (Oh) should be used, but if the net result of saving him until the end of the game is slowing down his usage rate, I guess we should all be okay with that.

Second, as you can see below, Oh’s fastball velocity has actually increased each month since joining the Cardinals:

One of the most obvious signs of an overworked pitcher is a decline in fastball velocity, and we are seeing the exact opposite with Oh. Sure, the scale of the graph (starting at 92 on the Y-axis is the main culprit) makes the climb look steeper than it really is, but still, a difference of 1.5 MPH is not insignificant. Plus, as we saw last night against the Mets, Oh flashed the ability to touch 97-98 MPH — something we have not seen all season — so one could argue Oh is as fresh as ever (his most recent outing prior to last night was Friday against the Phillies).

Bottom Line

Coming into the season, the “big three” out of the bullpen was always projected to be Rosenthal, Kevin Siegrist, and Oh. And as I stated in my opening paragraph, due to perpetual ups and downs, this so-called big “three” has really been a big “one and a half,” maybe (depending on which statistic you look at regarding Siegrist).

Rosenthal, the projected head of the “big three,” started a throwing program yesterday, but according to Mozeliak, in this piece by Brian Stull of St. Louis Baseball Weekly, they are still two weeks away from evaluating what’s next for the club’s former closer. With September just around the corner, the clock is ticking for Rosenthal to get back to active status and prove his effectiveness because his performance before the stint on the disabled list does not currently merit a spot on the postseason roster, should the Cardinals get there.

While not technically on the disabled list, Kevin Siegrist has not pitched since August 19th, five days after being removed from an outing due to “dead arm.” Again, as with Oh, big run differentials, combined with off days, allowed for such a lay-off, but at the same time, I’m with Bernie Miklasz on this one in that I’m not really sure what to expect from Siegrist the rest of the way.

Thus, the burden of the bullpen, in a vacuum, falls on Oh the rest of the way. The same reliever who has been used more often than all other MLB relievers except four. For a team fighting for a Wild Card spot, this can be slightly frightening, even if the 34-year-old’s velocity currently shows no signs of weariness.

Fortunately, baseball isn’t played in a vacuum, and the bullpen carries three other capable arms to help soften Oh’s future workload, just as we have seen in the games since the All-Star break. Two of these arms (Matt Bowman, Zach Duke) were smartly acquired at different points this season by general manager John Mozeliak. The other being the 21-year-old prospect Alex Reyes. As the Post-Dispatch’s Jose de Jesus Ortiz penned yesterday, it may feel like “time” to put Reyes in the starting rotation, but with both Reyes’ future and the Cardinals’ present (keeping Oh fresh) in mind, I’d, without a doubt, keep the flame-thrower in the bullpen for the rest of 2016.