Around this time last year, I wrote a post on MetsGeek taking a simple look at Manuel's bullpen usage. With Perpetual Pedro and Nightly Nieve living up to their names, I was interested in making some charts to take another look at the bullpen. One note, I used baseballreference.com and I believe the first game pitched counts as 6+ days rest, so adjust accordingly since I failed to do so.
As we can see, Felicano and Nieve pitch a ridiculously high number of games without any rest (11 and 10 games.) However, what concerns me more is that Mejia is third on the team in games pitched with no rest with 6. As mentioned on this site, Mejia is not pitching in many high leverage situations so the rationale for why he has the third highest percentage of games pitched with no rest is beyond me. Personally, with such a young arm that had never been used as a reliever before, I would prefer if Mejia's "days of rest" looked more like Raul Valdes. While I am ignorant what is best for a pitcher's arm, it just seems like a young arm making the transition from SP to RP would benefit from adequate as well as (mostly) consistent rest.
Obviously, the Mets have played in a number of extra inning and close games, thus the need for overusing RP is there. However, even with the latter consideration Frankie and Takahashi's usage looks pretty optimal. As they have been among our best RP, they have been used with no rest; however, they are also getting spots where they get a rest for three days. Of course looking at my other chart, while Takahashi usage has been great, he still is on pace 109 innings out of the bullpen. (Frankie is still sitting pretty, though his projected total innings would be above his innings pitched the past couple of years.) Honestly, I don't know how modern day starters do out of the bullpen and if we should be worried about Takahashi's projection and, along the same lines, Nieve's. I've heard that just as 120 pitches is the SP danger zone, 80+ games is (usually) the danger zone for RP but I'm not sure if there is an inning concern for RPs. I'm interest in hearing the community's opinion on this one.
Now, I should note, that last year my charts had Frankie on pace for 82 innings, J!J! on pace for 99 and Pedro pitching in 96 games. Of course none of these players came close to these numbers. Over the course of the season, whether it's regression, Manuel pulling in the reins or a season ending injury, these projected season ending totals will change.
Aside: I was going to look at preformace splits with regards to days of rest but the Mets pitchers are actually pitching very good (mostly ERA-wise) with no rest and poorly with 4 days of rest. However, the sample sizes are way too small to get anything out of so I decided to omit it.