With the news that Yu Darvish has spurned the Twins (and 28 other teams) for the Chicago Cubs, the Twins’ 2017-18 offseason has remained, until further notice, all about the bullpen.

The Twins have signed three free-agent relievers — Fernando Rodney, Addison Reed, and Zach Duke — to fortify a bullpen that finished last season 22nd in MLB in WAR, 22nd in ERA, 23rd in FIP, and 29th in strikeout rate. After adding its trio of relievers, the front office made the new additions’ roles clear: Rodney would be the closer, Reed the setup man, and Duke some additional lefty help for a team that allowed a .265/.333/.465 line against lefties last year.

Because we endured the Eddie Guardado Experience, Twins fans may not know this: the closer is not usually supposed to cause heart palpitations and incessant teeth grinding. The closer should be the stabilizer — the one who gets the ball When It Counts.

But Fernando Rodney is not, shall we say, a stabilizing force. La Velle Neal’s lede reflected this reality after the Rodney signing.

“Get ready for some nail-biting ninth innings,” Neal wrote to Twins fans on Dec. 15. (If it’s any consolation, fans of the Tigers, Angels, Rays, Mariners, and Diamondbacks can commiserate; the Google search “I Survived the Fernando Rodney Experience” yields 342,000 results.)

Rodney did blow six saves last season, but so did 21 other Major League pitchers. Like Guardado, Rodney is most notable not for his inability to close out games but the wild way in which he does so. Of the 155 qualified relievers in the 2017 season, Rodney ranked 131st in walk rate and 115th in percentage of pitches in the strike zone.

Rodney will also turn 41 before the start of the season, though, interestingly, his late-stage career hasn’t been defined by decline but by consistency. Rodney’s fastball has maintained good velocity into his later years:

Graph via Fangraphs

Though he’s generated fewer whiffs than most flame-throwing closers of this hyper swing-and-miss era, Rodney’s still consistently missed an above-average number of bats:

Graph via Fangraphs

While — and here’s the “nail-biting” part — always walking more batters than you’d like:

Graph via Fangraphs

Rodney is old but consistent. When weighing those two traits, however, his age can feel heavier. We’ve all seen pitchers’ arms explode or bodies break down in a hurry, and that big, bright “41” screams pretty loudly.

Looking at a list of relievers age 41 or older (there have been 36 who’ve thrown at least 50 innings since the Twins’ inception) reveals a few modern successes, namely Mariano Rivera, Trevor Hoffman, Doug Jones, Darren Oliver, Mike Timlin, and Jesse Orosco.

This group is self-selecting for success, granted, because if you make it to 40 and get to pitch more than 50 innings you’re probably a pretty exceptional pitcher. If you lower the minimum to five innings pitched to weed out position players (Ichiro, basically), you get a list of 79 reliever seasons, 35 of which ended with at least 0.5 WAR (Baseball Reference version). Relievers who start a season at 41 are usually insignificant contributors.

Rodney, for his part, doesn’t define himself by his age. “If you can control the game, it doesn’t matter how old you are,” Rodney told MLB.com’s Rhett Bollinger. “Closing is the situation in the game that I feel most comfortable. I feel like I can do my job.”

Whether Rodney can do his job will be the big bullpen question for the 2018 Twins. Because, in looking at the rest of the bullpen and the rest of the league’s closers, many Twins fans can’t help but wonder: is Fernando Rodney the right man for the job? And, if not, how long will he last as Twins closer?

Photo by Christian Petersen/Getty Images

Where does Rodney rank?

As any fantasy baseball player knows, the closer is a fickle beast. There are numerous Twitter accounts and email alerts designed specifically to notify fans when a team has changed closers to allow for the quickest e-acquisitions.

A list of all 30 closers is always going to shift and morph as the season goes on, but we have at least a pretty good idea of the 30 guys who will take the ball in the ninth inning to open the 2018 season.

Compared to his compatriots, Rodney resides somewhere in the 33rd-50th percentile in the stats most vital to a closer’s success: limiting baserunners/runs and generating swings-and-misses. By FIP, strikeout rate, and WAR, Rodney ranks 15th, 16th, and 17th respectively, out of 30; Rodney ranks 25th in both ERA and walk rate. There’s some average stuff and some bad stuff, which isn’t heartening.

As Pioneer Press beat writer Mike Berardino pointed out upon Rodney’s signing, “Rodney has 66 career blown saves and a career save conversation rate of just 82 percent. Thirty-one percent of his career inherited runners have scored, a high rate for someone entrusted with the ninth inning.” If Rodney is going to pitch exclusively one-inning, ninth-inning save situations, inherited runners aren’t a massive issue, but none of the above numbers engender trust.

When the Twins signed Addison Reed — a former closer who’s slammed the door shut 125 times in his career with a nearly identical save-conversion rate — almost exactly one month later, a source told Berardino that Reed’s arrival would not alter Rodney’s role, and the Twins higher-ups soon echoed that initial sentiment.

The Reed signing raised a few eyebrows, which Berardino conveyed in his lede in the Press. “For a team that’s supposedly laser-focused on adding to its starting rotation,” Berardino wrote, “the Twins sure seem to be spending a lot of time and money on their bullpen.”

The Twins’ approach does make a lot of sense: if (1) your bullpen is not that good and (2) your starting rotation is also not that good, adding relievers can fix #1 and relieve stress from #2. As teams carry more pitchers and rely on them to pitch fewer innings per outing, a deep bullpen can paper over a rotation’s deficiencies. It’s the blueprint that the Royals used to win back-to-back pennants in ‘14 and ‘15 and the Yankees deployed to devastating effect in last season’s Wild Card win over the Twins. It’s far more expensive to upgrade a team’s starting rotation, and a beefed-up bullpen can allow a subpar starter to only face a lineup twice to avoid incurring the dreaded third-time-through-the-order penalty.

After the three reliever signings, Twins chief baseball officer Derek Falvey acknowledged that the team needed to improve its pitching through any available avenue. “You don’t know, really, where things are going to go sometimes,” Falvey said. “So, the way we looked at it was, let’s find a way to augment our pitching. Ultimately, that could come in the starting rotation, that could come in the bullpen, but we knew we could upgrade.”

At least according to Baseball Prospectus’ PECOTA projection system, the bullpen acquisitions have improved the Twins’ pitching staff. PECOTA projects the Twins’ pitchers to accumulate 8.8 WARP in 2018, an improvement of nearly two wins over last season’s 6.89 WARP. Considering that the Twins seem likely to add at least one more starting pitcher via free agency or trade, that’s a good start for a net spend of $23.4 million over two years. (Duke and Rodney inked one-year deals, and Reed signed a two-year contract.)

You can’t have too much pitching, as the adage goes, but whether Rodney will remain the closer — and for how long — could become the central tension in the new-look bullpen.

Using their 2017 stats, I slotted a few of the Twins’ top relievers into Rodney’s closer role to see where they would rank compared to the 29 Opening Day closers. (The last column is the mean of their rankings, an admittedly crude way to try and gauge where they rank overall. I also excluded Duke because he’s never profiled as a late-inning guy or been discussed as such.)

These ranks are based solely on 2017 statistics. As I mentioned, PECOTA just released its projections for the upcoming season, and, if anything, they’re even lower on Fernando Rodney.

The Twins have brought in two former closers, Rodney and Reed, and the latter appears to be the superior pitcher by most any metric except IAF (Imaginary Arrows Fired) and 45dHR (45-degree Hat Rotation). The Twins also boast three returning relievers — Hildenberger, Pressly, and a recuperating Trevor May — as, at least on paper, viable in-house options.

I’m not suggesting that, coming off their first postseason appearance in several years with a young core, the Twins name Ryan Pressly or a just-injured Trevor May as their Opening Day closer; public perception-wise, that would be lunacy. I think adding Rodney, Reed, and Duke was a wise, affordable way to fortify the pitching staff.

But just take a look at Trevor Hildenberger: he was the Twins’ best reliever last season and should only improve this year, barring injury or unforeseen setback.

Hildy’s also remarkably similar to Rodney in that he relies heavily on a wickedly effective changeup out of the ‘pen. The below graph plots the frequency MLB relievers threw their changeups (Y-axis) against opponents’ Expected Weighted On-Base Average (x-Axis) on their change. No two pitchers in baseball relied as much on their changeups while also limiting loud contact on the pitch.

Graph via Baseball Savant

So perhaps this is the plan: Fernando Rodney, the grizzled vet, will mentor young Hildenberger and teach him to harness his changeup-throwing abilities to take another leap forward and surpass the old master. Or maybe Reed, the first outside free-agent reliever signed to a multi-year deal in Twins history, will take over the job in early May after Rodney’s third blown save.

But, if that’s the plan, no one told Rodney.

Rodney chose the Twins because, unlike other suitors like the Tigers or the Mets, the 41-year-old reliever said that the Twins guaranteed him the chance to close games, per Berardino.

Berardino also spoke with “a person close to Rodney” who made the Reed signing sound like a shot across the bow (the ship kind, not the arrow kind).

The Twins did not inform the 300-save closer of their interest in Reed before Saturday’s agreement went public.

“The Reed deal came out of nowhere,” that person said. “We’ll see how it plays out.”

We will see how it plays out. Rodney is by all accounts a great guy and a boon to the clubhouse, but closing out games seems important to him. With a few other good options and Rodney’s red flags, though, it’s fair to ask: how long will Fernando Rodney last as the Twins’ closer? And what will it mean for the bullpen — and the clubhouse — if the answer is “not long”?