Edwin Diaz utterly flubbed his first season as the Mets closer. After arriving in New York as the centerpiece of a momentous trade with the Seattle Mariners in late 2018, Díaz treated Mets fans to one of the most frightening relief-pitching experiences in recent memory. He finished with a career-low 71 ERA+ just one year after finishing eighth in the AL Cy Young Award vote with a league-high 57 saves and a career-high 208 ERA+. He gave up 15 home runs in 2019 after giving up just 15 in the previous two seasons combined, and midway through the season he lost his closer role and was relegated to middle-relief.
It’s reasonable to conclude that Díaz’s seven blown saves were the single biggest factor in the Mets missing the playoffs in 2019, and many fans wondered whether he could regain his all-world form he had in Seattle. He still produced electric movement on his fastball and registered an impressive 15.4 strikeouts per 9 innings, but also gave up a ghastly 2.3 home runs per 9 innings and consistently allowed hard hit after hard hit. The Mets are no stranger to inconsistent production from their closers, but no closer in franchise history had higher expectations and a worse opening act than Díaz.
2020 started much the same for Díaz, with a blown save in just his second appearance against the Braves. He didn’t get another save opportunity until August 26th against the Marlins, which he blew, and after recording a save two days later against the Yankees, he blew another two days later in one of the most frustrating appearances of his career. At the end of August, Díaz had accounted for two saves, one hold, and three blown saves. His second chance as Mets closer did not look promising.
And then September came, and with it a return to form for the former All-Star. Díaz began the month with two innings of retribution against the Yankees and then delivered on his potential throughout the month. He gave up just one run in eleven September appearances, giving up only five hits and six walks while striking out twenty batters. Díaz finished the month with a sub-1 WHIP and finished the season with an astounding 17.5 strikeouts per 9 innings, recording four more saves along the way in recovering his closer role. To say he was back to form feels premature with such a small sample size, but for one month Edwin Díaz was unhittable.
Though it’s not entirely clear whether this contributed to his mid-season improvements, Díaz produced significant changes in pitch movement compared to 2019. According to Brooks Baseball, the horizontal movement on his fastball increased significantly in 2020 from years past, making an already nasty pitch downright disgusting. Conversely, Díaz also produced much less vertical movement on his slider, which in the abstract seems bad, but perhaps made it more difficult for hitters to determine the pitch out of his hand. Combining these changes in movement with consistent high velocity over his career, it’s reasonable to conclude these changes had significant positive effects on his performance.
Another potential influence on his performance this season was his lessened use in high-leverage situations. In 2020, manager Luis Rojas only inserted Díaz in eight potential save situations, making up just 31% of his relief appearances. In 2019, a year where Díaz lost his role midway through the season, he saw 44% of his appearances come in potential save situations. These numbers might not mean much when he seems to have pitched his best during a month where he somewhat regained his closing role, but it’s clear the club used him more cautiously in 2020 than in 2019.
It’s now up to the front office to determine whether Díaz will retain this success or will better resemble the Díaz of 2019 and early 2020. With only two more years of team control before he becomes an unrestricted free agent, Díaz makes a decent candidate for an extension this offseason. And even if there’s enough evidence to indicate Díaz deserves an extension, the front office’s ultimate decision might have less to do with his performance and more to do with the current market value of relief pitchers.
If the Mets believe that Díaz is now the All-Star caliber closer they traded for, then conventional wisdom suggests they offer him an extension simply to keep a great pitcher on the roster. After all, the 2020 playoffs demonstrated the value of an effective bullpen, with the Dodgers and Rays both leaning heavily on their relief pitching en route to the World Series. Díaz could play heavily for the Mets in the coming years even outside of the closer role.
But even if the Mets believe that Díaz is something less than All-Star caliber, which is a safer bet, they still might want to offer an extension anyway due to the severely depressed relief pitcher market. Just like we saw during the 2018 offseason, MLB owners’ increasingly miserly financial proclivities have already started to squeeze the middle class of players this offseason, and no one better represents MLB’s middle class than a productive relief pitcher. The penny-pinching Indians waved their All-Star closer Brad Hand, making him available to any team for a reasonable $10 million price. But despite having the option of picking up an All-Star caliber pitcher seemingly at below market value, not a single team picked him up.
Similar forces left quality players searching for scraps in a depleted market in 2018, forcing stars like Ozzie Albies to settle for team-friendly extensions in the face of an uncertain financial future. Hand is the first big-name player to fall victim to this in the 2020 offseason, and he likely won’t be the last. MLB’s middle class, and relief pitchers especially, will likely see offers well below what they would have seen just a few years ago. Díaz certainly falls under this umbrella, and unless the owners drastically change their spending habits over the next two years, he likely won’t see the contract offer he deserves.
Díaz’s misfortune is the Mets benefit in this circumstance. Díaz is clearly an above-average relief pitcher and finished this past year with an elite month-long stretch. That alone should merit an extension, especially if new owner Steve Cohen flexes his financial resources and increases the payroll. And if extending Díaz comes at a well-below-market price, than drawing up a new contract is a no-brainer. On a team-friendly deal, he doesn’t need to be Seattle Díaz or September Díaz to provide value to the team, and it would provide low risk to a potentially sky-high reward.