Which recent Yankees relievers threw the most innings in a season?

Michael King may be exclusively working out of the bullpen for the Yankees, but that hasn’t stopped the Yankees from limiting the amount of innings he has thrown. Between his top-tier stuff and his ability to go multiple innings on a regular basis, he has already thrown 19 innings for the Yankees, first on the Yankees by far and second in all of baseball — only Chicago’s Keegan Thompson has thrown more while working exclusively out of the bullpen.

Now, at this point, you might be asking, “Yes, but just how unusual is that?” — understandably so, since early-season sample sizes can shroud the reality of a pitcher’s usage. Well, at the moment he is currently on pace to throw 114 innings, which would be the most a Yankee pitcher has thrown in relief in a very, very, very long time. Just how unusual is that? In the past 30 years, only Dellin Betances, Scott Proctor, Paul Quantrill, Ramiro Mendoza, and Mariano Rivera have thrown 90 innings or more without making a start. Let’s take a look at how they did it.

Dellin Betances, 2014 — 90.0 innings

Entering the 2014 season, Dellin Betances was a former top prospect thrust into a bullpen role as a last-ditch effort to try to make him an effective reliever. Needless to say, it worked, as the 6-foot-8 right-hander quickly established himself as one of the premier pitchers in baseball. Although working exclusively in low-leverage at the beginning, he quickly established himself as one of Joe Girardi’s most trusted arms. As a former starter, he was more than comfortable going multiple innings at a time: he threw more than one inning half the time, and even got seven outs twice.

This versatility made Betances one of the most valuable relievers in baseball — his 3.7 bWAR, in fact, was second on the Yankees (behind only Brett Gardner), and his 3.0 fWAR was second among relievers (behind only Wade Davis). He finished the season as a much-deserved finalist for AL Rookie of the Year, finishing third. For a team that had just seen the greatest relief pitcher of all time in Mariano Rivera ride off into the sunset, Betances was a welcome reinforcement.

While injuries and a late breakthrough made Betances’ career short and bright, at his height, he was by far the best in baseball.

Ramiro Mendoza, 2002 — 91.2 innings

From 1997 to 2001, Ramiro Mendoza did it all for the Yankees. When they needed an extra starter, he did that, making 46 starts across five seasons. When the bridge to Rivera needed reinforcements, he came out of the ‘pen. While he was not an elite arm (he posted a 3.93 ERA and 4.07 FIP in that span), his versatility made him invaluable.

The 2002 Yankees did not need Mendoza to start, as they already had Roger Clemens, Mike Mussina, Andy Pettitte, David Wells, and Orlando Hernández, to which they added Jeff Weaver in July. That allowed Mendoza to remain in relief, where he excelled as a multi-inning reliever: he threw one inning or less in just 25 appearances, while going two or more in 22. Furthermore, he went three or more seven times, filling a mop-up role, providing multiple high-leverage innings when the starter had to come out early, and eating innings to preserve arms during long extra-inning outings.

Like everything Mendoza did, it wasn’t glamorous, but it was valuable.

Paul Quantrill, 2004 — 95.1 innings

Truth be told, when I started this list, I thought for sure that Paul Quantrill had reached 100 innings. After all, it seemed like he had pitched in every single game for the Yankees that year. In truth, he “only” pitched in 86, and looking back at his game logs, it’s easy to see why he didn’t pitch more down the stretch. After posting an ERA of 3.00 through August 14th, he allowed 25 runs in 20.1 innings over his last 22 appearances, with opposing hitters slashing .454/.500/.598 against him.

Still, in hindsight, it’s not surprising that Quantrill started to break down. He had led the league in appearances for three straight seasons prior to 2004, and had thrown 77 or more innings in every year since 1997 except for 1999. At 35 years old, it was only a matter of time before the innings would catch up to him, and unfortunately for the Yankees, it came during his time in pinstripes.

Scott Proctor, 2006 — 102.1 innings

Looking back, Joe Torre’s biggest flaw as a manager was that he relied too much on his top relievers, overusing and wearing out his top arms. Nobody represented that flaw better than Scott Proctor.

A long reliever/mop-up guy at the back of the ‘pen from 2004 to 2005, Proctor broke out in a big way in 2006. Not only did he lead the league in appearances with 83, half his appearances were of more than one inning — he went two or more innings 14 times, and even went three innings twice. He had become, alongside Brian Bruney, the bridge to closer Mariano Rivera.

Photo by Chris Trotman/Getty Images

Proctor would repeat his regular usage in 2007, although this time he did it split between the Yankees and Dodgers. Ultimately, these two seasons would torpedo his career. He spent most of 2008 on the shelf and missed all of 2009 with a torn UCL; when he returned, he never came close to his old self. But for a brief time, Proctor was arguably the most important reliever on one of the best teams in baseball.

Mariano Rivera, 1996 — 107.2 innings

All-time saves leader. Last player to wear No. 42. First unanimous Hall of Famer. The namesake for the American League Reliever of the Year Award. The greatest reliever of all-time. It’s only fitting that our list ends here.

Mariano Rivera has an immense amount of accolades to his name. But in many ways, his most amazing accomplishment is one that he very rarely gets credited for: his 1996 season. A failed starter who had transitioned to the bullpen and who had almost been traded for a stopgap shortstop during the winter, Rivera spent much of 1996 as the setup man for closer John Wetteland, and his performance was historic by any measurement you use. He posted just a 2.09 ERA in 107.2 innings across just 61 appearances, limited opposing pitchers to less than a hit per inning and just one home run combined.

Baseball-Reference credits him with 5.0 bWAR, a mark that no reliever has matched since. FanGraphs pegged him at “just” 4.3 fWAR, good for 23rd in baseball among pitchers with at least 100 innings and more than a full run ahead of second-place Roberto Hernandez. To put it simply, Mariano Rivera was so effective in relief that he was as valuable as an upper-level starting pitcher.

Part of what made Rivera so valuable was the fact that he regularly went more than one inning. 41 of his appearances went longer than one inning, while 35 were two or more. Eight times, he was on the mound for three innings or more. Every single one of them was an elite outing: he allowed a run in only 13 of them, and multiple runs just seven times. On the back of this performance, he finished the season as a finalist for the Cy Young Award — a rare feat for a reliever, and practically unheard of for a setup man.

It’s easy to see why the Yankees decided to let Wetteland walk, and hand the closer’s job over to the Sandman. Although he never came close to this innings total again, the Yankees surely did not regret the move, as they had a safety net in the back of the bullpen as reliable as there could possibly be.