This has been an exciting year for rookie performances. Juan Soto has looked like the best teenage hitter in history, Ronald Acuna has helped lead the Braves to a (surprising) lead in the NL East, and Shohei Ohtani has short-circuited our understanding of player value with his two-way achievements. Rookies have always been a key component to baseball’s excitement, and this year’s crop is no exception.

Now, quick: what player leads rookies in second-half WAR? If you guessed Acuna, congrats! Acuna has caught fire, putting up a 190 wRC+ and 3.4 WAR since the break — second-best in baseball behind Matt Chapman’s 3.7 mark during that timeframe.

Let’s continue, though. Who’s second amongst rookies since the break? Soto? Sorry, no. Ohtani? Nope, not even after accounting for his contributions on all sides of the ball. It’s not the workman-like Brian Anderson, nor is it defensive wizard Harrison Bader. No, second among rookies in WAR during the second half is New York Mets second baseman Jeff McNeil. For some, perhaps that makes sense. For many, though, the likely response is, “Who?”

That’s understandable. Unless you’ve watched a Mets game since July 24th — and let’s be honest, why would you if you lived outside the New York MSA? — you’ve probably not heard of McNeil. Even if you were a prospect hound, McNeil could have evaded your eye. He didn’t appear on prospect lists for the Mets here at FanGraphs, at Minor League Ball, or Baseball Prospectus. At FanGraphs, only the enigmatic Carson Cistulli mentioned McNeil in an early July edition of the Fringe Five.*

*Since this article came out, it has come to my attention that several articles focused on or mentioning Jeff McNeil have been written by several authors. Among them include the Baseball Prospectus and Baseball Prospectus Mets prospect writers Jarrett Seidler (May 2018), Jeff Paternostro, and Alex Rosen (May 2018). Jeff’s coverage of McNeil in particular goes back as far as McNeil’s second season in 2014. This oversight was completely accidental on my part and not meant to disregard or disparage their work or the work of anyone else who has written about McNeil in the past

For a Mets fanbase that has observed the front office regularly block prospects in favor of flawed veterans — at least they finally freed outfielder Brandon Nimmo — it has to be mildly gratifying to see a young player getting reps in the waning days of the season. McNeil is not only second in WAR amongst rookies in the second half, he is 13th among all hitters by the measure.

Given McNeil’s lack of obvious tools, there’s still reason to doubt that he can put together a substantive major-league career, let alone sustain the pace he’s established since July. Despite these concerns, however, it’s encouraging that the Mets have continued to give McNeil — and Amed Rosario and Nimmo — sufficient playing time to earn a place on the big-league club.

McNeil has never resided atop prospect lists. Drafted in the 13th round out of Long Beach State, whatever positive traits McNeil possessed as an amateur were accompanied by negative ones. He had good bat control… but no power. His fielding actions were smooth… but not flashy and were backed by a fringe arm. He seemed destined for a utility bench role in the majors… if he could get there.

In the minors, McNeil made the most of his opportunities by playing to his strengths. He showed good bat control, hitting over .300 in every stop at which he received at least 100 PAs. He showed plate discipline and control, striking out well below league average and putting up a 0.7 BB/K ratio over his entire minor-league career. For a player capable of handling — if not excelling at — second base, third base, and the outfield, the offensive skills were promising.

Then a funny thing happened in 2017. To that point, McNeil had posted isolated-power marks in .070 range, nor did there seem to be much room for more. In 2017, though, that ISO figure jumped to around .130. Then, in 2018, before his callup, his ISO was around .250 and he had hit 19 home runs — 10 more than his 2013-17 seasons combined.

The underlying numbers backed up this assessment. When he entered professional baseball, McNeil put the ball on the ground anywhere between 45% and 50% of the time. In 2017-18, that number has been closer to the 35-40% range. Pairing his bat control with a change in swing plane would allow McNeil to tap into more of his power, without necessarily striking out at a prohibitive rate.

Since arriving in Queens, McNeil has followed many of the tenets that brought him to the majors. The power isn’t as prodigious as in Double-A or Triple-A; his .154 ISO is still serviceable, though. He isn’t striking out (8.7%) and still has a walk-per-strikeout rate close to his minor-league rate (0.67 versus 0.70). His swinging-strike rate of 7.8% suggests that bat control has followed him to the majors, as does his .367 BABIP. The offensive package seems to be exactly what we would expect him to need for major-league survival: his minor-league profile with a little more power. As an added bonus, he has been a positive on both the basepaths (2.9 runs’ worth) and in the field (2.2 per 150 UZR at second base).

McNeil’s profile definitely comes with questions. His exit velocity of 85.6 mph places him 314th among the 375 hitters to record 100 batted-ball events. His barrels per PA of 2.4% ranks 306th within that same sample of players. This seems to suggest that an average ISO of .150 might be a stretch, even with a launch angle of 13.6 degrees. Further, his sprint speed of 27.6 ft/s combined with the lack of exit velocity suggests that the aforementioned BABIP may be unsustainable. Additionally, with a sprint speed of 27.6, the 2.9 baserunning runs may be a stretch to maintain — even if sprint speed isn’t everything.

Even though McNeil seems likely to experience some sort of natural regression in performance, he still is definitely something for Mets fans to enjoy in the present. He may even be able to maintain his performance, and it’s possible that this exit velocity is low by his previous standards. But there’s one question that McNeil’s performance, promotion, and continued playing time should cause Mets fans to ask: “Why is McNeil here and Peter Alonso isn’t?”

Both players tore up the Eastern and Pacific Coast Leagues this year, so what separates them? Well, of course, Alonso is not only one of the Mets’ best prospects, but one of the best in baseball. McNeil, as we mentioned earlier, has never sniffed the top of any prospect lists. Is it possible that the Mets promoted McNeil because they did not see him as a future cornerstone and therefore are less concerned about his service time? It’s certainly possible. And as Baseball Prospectus’s Craig Goldstein eloquently wrote last week, while we understand the financial concerns that drive service-time questions, the practice can and should still drive fans up a wall.

The Mets’ front office has seemingly started to allow the next generation of Mets players to arrive. This year, we’ve seen significant playing time given to Rosario and Nimmo, while Dominic Smith has finally has been recalled after yoyo-ing from New York to Vegas. Yet, in certain cases, the team is still hesitating to hold off starting the clock on players they deem as future pieces while lesser lights are allowed their chance. Jeff McNeil had provided sufficient proof at the minor-league level, and his major-league performance has rewarded the team with a glimpse of what he could potentially be going forward. Maybe it’s too much to hope, but perhaps McNeil’s second-half numbers will show the Mets that there are advantages to giving all players — whether they are likely to be franchise cornerstones or replacement players — the opportunity to excel at the major-league level once they’ve proved all they can in the minors.