How badly do the Cardinals need to upgrade at closer?

Relative to baseball as a whole, and relative to past iterations of the team, the St. Louis Cardinals have been relatively stable at the unofficial position of closer. While the position had some shakiness in the early 2010s—Ryan Franklin was designated for assignment in 2011, which led to a few months of Fernando Salas, which led to Jason Motte finishing 2011 as the don’t-call-him-a-closer closer, and then acting as the sole save accumulator for the 2012 Cardinals.

But once Motte was injured before the 2013 season, the role was filled by Mitchell Boggs, who had a 2011 Franklin-esque tenure despite a generally productive tenure as Jason Motte’s setup man the season before. Edward Mujica took the closer role immediately after, but after he too suffered a bit of a productivity dip later in the season (more in line with that of Salas than that of Franklin or Boggs, to be fair to Mujica).

The next man up was Trevor Rosenthal, who had performed excellently in the bullpen throughout 2013 (and in a lesser capacity in 2012). He continued to impress and remained in the role throughout the 2014 and 2015 seasons. He struggled in 2016 when, conveniently, Seung-Hwan Oh stepped up and became one of baseball’s best relievers. And in 2017, when Oh struggled, Rosenthal was back in vintage form.

The plan for the bullpen entering 2018 appeared to center around Trevor Rosenthal, once again the team’s top reliever and a player with one year of salary arbitration remaining before he hit free agency following the 2018 season. The Cardinals stood pat at a trade deadline where it was expected that other playoff contenders would pursue Rosenthal, partially to compete in 2017 but also seemingly as a signal that they expected Trevor Rosenthal to be a big part of their plans in 2018.

But following a late August injury, which required Tommy John surgery which will force Trevor Rosenthal to miss most, if not all, of 2018, a wrench was thrown into the team’s long-term plans.

The Cardinals’ response to Rosenthal’s injury was trading for Pittsburgh Pirates-turned-Philadelphia Phillies reliever Juan Nicasio, who pitched well for the Cardinals but was a distinctly short-term acquisition: Nicasio was only under contract through the end of the 2017 season and because he was traded in early September, he wasn’t even eligible for the Cardinals’ postseason roster. He was a rental even by the standards of rentals.

Long-term, however, the Cardinals have less bullpen depth than they did before, a fact which was going to be true entering the off-season even had Rosenthal not been injured. Recent bullpen mainstay Kevin Siegrist was designated for assignment late last season and claimed by the Phillies. Seung-Hwan Oh and Zach Duke will each be free agents. And if Lance Lynn departs via free agency, and the Cardinals use an internal replacement for him in the starting rotation, the Cardinals will have one more potential bullpen option unavailable to them.

Adding fuel to the bullpen fire was Cardinals president John Mozeliak’s comments on local radio on Thursday, in which he intimated that the top priority for the Cardinals in the off-season is a closer. He also indicated that said closer will likely come from outside of the organization.

To get the obvious point out of the way: yes, the Cardinals would benefit from a top-flight closer, somebody at the Trevor Rosenthal level or better. I would dare say they’d be even better if they acquired two top-flight closers. In fact, if the team were to acquire half-a-dozen top-flight closers, well, that would be downright nifty.

But should a big-time closer be the primary focus for the Cardinals, as opposed to, say, acquiring a major middle-of-the-order bat? In a vacuum, the best hitters are more valuable than the best closers—baseball’s most valuable reliever in 2017, Los Angeles Dodgers closer Kenley Jansen, was worth 3.5 FanGraphs Wins Above Replacement, while baseball’s most valuable position player, New York Yankees right fielder Aaron Judge, was worth 8.2 fWAR. Jansen was great, but at 68 ¹⁄₃ innings pitched, his innings total was just a third of the total accumulated by Carlos Martinez.

But the market should act relatively in line with this value difference—even if Jansen weren’t on a free agent contract or Aaron Judge weren’t five seasons away from reaching free agency and the two had identical contract terms, every team would recognize that Judge is more valuable. And if a team’s bullpen is that much worse than its lineup, it makes more sense for that team to acquire relievers.

In 2017, by fWAR, the Cardinals bullpen ranked 12th among MLB bullpens, meaning they were slightly above-average. By earned-run average, they fared even better, ranking seventh. By fielding-independent pitching, eighth. By xFIP, 12th. The perception of the Cardinals bullpen as an extreme weakness did not match the numbers.

But even I’ll admit that the bullpen looks considerably weaker without the presence of some key members. 1.6 of the pen’s 4.4 fWAR came courtesy of Trevor Rosenthal, and the potential departure of Juan Nicasio, the only reliever in the same stratosphere of Rosenthal on a rate basis, does leave the Cardinals without a reliable relief ace. The most valuable 2017 reliever under contract for 2018 is the much-maligned Brett Cecil, and while Cecil is a strong candidate to surpass his 2017 production, he is hardly a certainty to rise to levels he has never reached in his career, much less in 2017.

But how necessary is it to enter a season with an elite closer if the ultimate goal is a title? Here’s a look at the closer situation for some recent World Series champions.

• 2016 Chicago Cubs: After beginning the season with Hector Rendon, the Cubs acquired Aroldis Chapman at the deadline. By the end of the season, the Cubs had a high-end closer, but entering the season, the team set forth as World Series favorites with 2015’s fourteenth most valuable reliever.
• 2015 Kansas City Royals: The defending AL champions entered the season with an elite closer in Greg Holland, but he was decidedly mediocre throughout 2015 before a UCL tear necessitated Tommy John surgery. His replacement was Wade Davis, already an elite setup man—a player acquired by the Royals as an afterthought from the Tampa Bay Rays in the James Shields-Wil Myers trade. And now, both players will be rumored as (much more expensive than in 2015) closer solutions for the Cardinals in 2018.
• 2014 San Francisco Giants: The Giants began the season with Sergio Romo, perfectly fine though not quite elite, as closer, but after ineffectiveness, the Giants moved to a closer-by-committee approach around mid-season. By season’s end, the de facto closer was veteran journeyman Santiago Casilla, though he was less trusted than “Madison Bumgarner on short rest in an extended relief appearance” in Game 7, so take that as you will.
• 2013 Boston Red Sox: First, it was Joel Hanrahan. Then it was Andrew Bailey. But for most of the season, including the postseason, the Boston closer was control artist Koji Uehara. Although he was superb in 2013, he had been relatively under the radar prior to 2013 in his prior stints with the Baltimore Orioles and Texas Rangers.
• 2012 San Francisco Giants: The aforementioned Sergio Romo was closer by season’s end, but it was Brian Wilson who began the season as the team’s go-to ninth inning pitcher, before an injury which required Tommy John surgery in mid-April.
• 2011 St. Louis Cardinals: As mentioned above, the closer carousel eventually landed on Jason Motte.

There is, to be fair, selection bias at play here. The previous four World Series winners to 2011 had established closers, including some elite ones: Brian Wilson, Mariano Rivera, Brad Lidge, and Jonathan Papelbon. And this year’s World Series champion, be it the Los Angeles Dodgers (Kenley Jansen) or the Houston Astros (Ken Giles), will have an established closer.

But a team doesn’t need an established closer to win. The only relatively sure-thing closer on the free agent market will be Wade Davis, and he will be expensive. It would certainly help the Cardinals’ odds to improve the bullpen, but even just re-signing Juan Nicasio and hoping one or two of the younger relievers emerge could be sufficient. The Cardinals, to be clear, should do other things, too, to improve their odds of making the playoffs, but it would be a mistake for the Cardinals to fall for the bullpen as a scapegoat when the team has other routes to improve the team more dramatically.