Replacing Joe Nathan

For the past six seasons the Twins haven’t had to think about the ninth inning. If they had a lead in a close game, Joe Nathan was there to ensure victory. In only 25 of 272 instances did he fail to deliver. This year, though, the Twins will likely have to turn to someone else. News broke this morning that Nathan has torn his UCL and will probably undergo surgery before the season starts. He’s waiting two weeks to see whether rehab is an option, but at this point we can safely assume Tommy John surgery lies in his immediate future.

At RotoGraphs, Eno ran down Nathan’s possible replacements. The in-house options are pretty obvious: Jon Rauch, Pat Neshek, and Matt Guerrier. None of them stands a good chance to replace Nathan’s dependable production, but the effect on the closer role itself isn’t the Twins’ biggest problem. As Matt Klaassen has been saying all morning, they’ll lose perhaps two wins from that spot. There are larger implications, however, as Nathan’s absence cascades through the Twins’ bullpen.

For most positions, we define replacement level as the production of a AAA player called up to the bigs. This is not the case for closers. Replacement level for that position is the team’s next best reliever. When that next best reliever moves into the closer’s role, everyone else in the bullpen moves up, too. Relievers lower on the depth chart play a more prominent role. The biggest effect, then, comes at the back end of the bullpen, where the replacement level player shows up.

Teams, for the most part, can avoid using the seventh reliever on their staff in high leverage situations. But what of the former seventh reliever? He’s now the sixth reliever and will be pressed into more active duty. Such is the curse of bullpen chaining. About a year ago, Sky explained the process. His model agrees with Klaassen’s two-win estimate, but it also assumes a closer with a 3.00 ERA. The closest Nathan came to that was 2.70, and that happened five years ago. Clearly, unless one of the in-house replacements really takes to the role, as Nathan did when the Twins traded for him, the effect will be larger.

There’s no doubt that the Twins will miss Nathan’s dependable ninth inning performances. What they’ll miss more, though, is having guys like Guerrier, Neshek, and Rauch in setup roles. By moving them up in the pecking order, they’re allowing other, possibly lesser arms into the bullpen mix. That will hurt more than the mere ninth-inning downgrade.

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Joe also writes about the Yankees at River Ave. Blues.

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mattymatty
Guest

Really? The worst part about the Twins losing Nathan for the year is having a lesser reliever leave a less important role? That doesn’t sound right to me.

Tom B
Guest
Tom B

you missed it. it’s having a lesser reliever step into a more important role.

it’s a greater difference(detriment) to have your worst reliever pitch more than than to have the setup man take over the closer role.

mattymatty
Guest

I think you missed it. Read this again:

“There’s no doubt that the Twins will miss Nathan’s dependable ninth inning performances. What they’ll miss more, though, is having guys like Guerrier, Neshek, and Rauch in setup roles.”

chuckb
Guest
chuckb

Matty — you may notice that the quote you referred to is exactly what Tom mentioned, that lesser guys will have to take more prominent roles. So he didn’t miss it; he nailed it. The Twins will need to find a 7th or 8th inning reliever (hello Russ Springer?) rather than worrying about what they’ll lose in the 9th.

Tom B
Guest
Tom B

Precisely Chuck. The impact of your AAA reliever pitching at all and your 6th/7th/mop up guys pitching in more important situations is huge. Larger than the difference between Nathan and the set-up man.

The article was written in more generality than the Twins specific situation. They didn’t have a defined “set-up” man, so it seems more painful in that respect than it should be.

wobatus
Guest
wobatus

I think Matty is right. They will suffer more from having one of their high 3 to low 4 xfip guys moving into replace a sub 3 xfip guy as a closer than in trying to have a youngster come in and fill the 4.3 or so xfip 5th guy in the bullpen roll. Rauch, Neshek, Guerrier and Mijares is decent depth. Any way you look at it, it is going from a sub-3 xfip guy to an unknown rookie or waiver pick-up type (Joe Beimel still out there I hear). But Nathan’s innings were higher leverage.

wobatus
Guest
wobatus

Tom B, I think that is wrong. Rauch’s projected fip per CHONE is 2.96. Rauch is 3.96. Mijares 4.4. Guerrier 4.49. Neshek isn’t projected by CHONE, but splitting James and Marcel, plus injury risk, say he is also aout 4, or 3.96 like Rauch (although if he is healthy he would be the guy in my mind).

From nathan to any of those guys you are talking a 1 run FIP falloff at a high leverage relief situation. Then there are 3 guys after that slot. I forget who else the Twins have, but you are talking about the 12th guy in the pen now who is being replaced. Everyone else come up a tad. Condrey is the 6th inning guy. Some scrub is now mop-up. That aspect of it isn’t that big of a deal, if your lowest leverage arm goes from a 5 to a 5.5 fip. And the set-up guys are fairly even in rank. Nathan to rauch, for example, that seems to me to be the bigger deal.

As someone else pointed out, calero just signed a minor league deal. Joe Beimel is out there. His projected fip is 3.92.

We are talking about some kid in the minors having to have a worse than 5.5 fip, at a lower leverage slot. Sure, everyone else moves up, and your 7th and 8th guys can be even higher leverage. But between Mijares and Guerrier there ain’t much difference fip wise. if you need to 7th guys, an 8th and a closer, well, the twins will have that still (Neshek, Rauch Guerrier and Mijares).

Jason B
Guest
Jason B

Rauch is 2.96 and 3.96?

wobatus
Guest
wobatus

Jason B., sorry, Nathan is 2.96, rauch is 3.96.