Nationals reliever Koda Glover delivers against the Phillies last month. (Katherine Frey/The Washington Post)
Columnist

It’s far too soon to know what Koda Glover will be. But it’s not too soon to recognize what the Nationals’ closer has done in a third of his rookie year, how impressive his four-pitch arsenal has looked against big league hitters and how aggressive and imposing yet calm he appears while doing it.

In fact, it would be oblivious and no fun at all to ignore the possibility that the Nats, their bullpen aflame a minute ago, might have found their closer of the future.

They also might have a crucial back-end piece for a postseason run this year. But for their season to have the coda they want, the Nats need the wisdom to reduce pressure on Koda and protect his proper development by pursuing a trade for an established closer before the Aug. 1 deadline. Glover, plus another.

Don’t jump up and down. Baseball is often fabulous just before it turns cruel. Long ago, Glover had Tommy John surgery. Last year and again in April, he went on the disabled list with hip pain. Maybe he’s just healthy and in a hot streak right now, elated at getting the closer job he adores, saving four games in a five-game span before taking a day off Wednesday.

And maybe not. Maybe Glover, whose first name means “Bear” in his Cherokee heritage, is considerably more than a rookie in a groove.

The Nats need to maximize that possibility. To resist overworking Glover — and so they have October options as to who pitches the eighth or the ninth inning — the Nats need to land David Robertson, Kelvin Herrera, Tony Watson or even Mark Melancon in a trade. Then, with one final fix — healing the confidence of Blake Treinen so he can resume the valuable high-leverage role he held last season — the Nats might go from a bullpen that brought tears in April to one that is feared in the fall. What are we looking at in Glover?

When you want to identify MLB’s dominant closers, you use the eye test: Watch the pitcher’s stuff, then see how feebly the hitters react to it.

You also go to the numbers to look at stats that coincide with dominance. Who prevents hitters from reaching base (walks plus hits per inning pitched)? Even better, who keeps them off base and doesn’t allow many extra-base hits either (on-base-plus-slugging-vs.)? Who induces a high percentage of groundballs, which never become homers but often turn into double plays (GB%). Also who has the combination of stuff and control for a high strikeout-walk ratio (K/W)?

The same closers dominate those categories again this season: Craig Kimbrel, Kenley Jansen, Wade Davis, Greg Holland, Dellin Betances and Aroldis Chapman monopolize the top spots (among relievers with five saves).

But one other name appears among the leaders: Glover. He ranks third to sixth in all the categories mentioned above: 0.81 (WHIP), .441 (OPS-vs.), 51.1 (GB%) and 8.0 (K/W). Also, his ERA is 2.08.

The eye agrees with the stats. Glover’s slider is the fastest in the game (93.2 mph), ahead of Noah Syndergaard’s (92.4). Last week, Glover threw a 95.6-mph slider — one of the 10 fastest since measurements began in 2008 — that swerved so much and so late that catcher Matt Wieters barely snagged it.

Glover actually throws more sliders than fastballs, bad news for hitters who usually hate breaking balls but also worrisome because sliders can be elbow-eaters.

The 6-foot-5, 225-pound right-hander has a fastball a tick ahead of Stephen Strasburg’s (96.4 to 96.3 mph). Glover’s heater also sinks, thus all those grounders. He’s one of four closers this season who have allowed no homers.

Many closers — Kimbrel, Davis, Holland and Betances — throw just two pitches, polishing them so each appearance will be sharp. Less complexity to fret about. Just three closers use four pitches. Glover is one of them, throwing an 80-ish curveball and a high-80s change-up almost 14 percent of the time combined. So a hitter may see 98, 93, 87 and 79 in a row. That’s not nice.

Can Glover keep all those pitches precise? Now, he’s throwing two-third strikes and getting ahead in counts so often that he rivals Max Scherzer among Nats for the fewest pitches per inning (15.05 to 15.06). In style terms, Glover is an odd hybrid: He’s more a sinker-baller than most Monster K closers but more a strikeout pitcher than groundball guys such as Melancon. Is that sustainable?

Let’s not fall for Glover’s stats too fast. “Small sample size” means that just one bad inning — a bloop, a walk and a blast — and he’s not atop those leader lists anymore. On the other hand, Glover was overpowering as he flew through the Nats’ minor league system in just 14 months, then was excellent in his first dozen big league games last year until he was hurt.

Beneath his mohawk and goatee, Glover is still one of those tingling baseball mysteries. He has flaws. He may have neglected his hip rehab exercises, thinking he was fixed, and ended up back on the DL in April. Plenty of tests await him — such as facing the best lineups. But this week he closed three straight games — a necessary threshold for closers — and though he wasn’t as crisp in the final game, he still erased the Giants’ 2-3-4 hitters and fanned Buster Posey to end the game.

Not long ago, two top Nats decision-makers doubted they had a World-Series-quality closer in house, though both looked at Glover as the most likely to have the physical and mental resilience for the job. Also, what rookie deserves to face such pressure immediately? “K-Rod [Francisco Rodriguez] did it as a rookie” for the 2002 Angels, one of them said. “But it’s probably an unfair thing to ask.”

It is unfair. And also foolish.

The Nats have stolen a potential diamond with the 254th pick in the 2015 draft. (How do they keep doing it?) But in a season when the Cubs seem post-title flat and no one in the National League is clearly better than Washington, the Nats have a big fat chance, just like 2014. Ownership needs to step up.

Glover and journeyman Matt Albers, having a career spring, may feed delusions this could be a pennant-winning bullpen as it stands. It isn’t. Not even if Glover saves seven of every eight chances, as he has so far. It’s one big arm shy.

By Aug. 1, as teams fall out of races, several such arms will be available. In some cases, the big cost will be assuming salary, not trading away prospects. If the Lerners balk at money, at least on the scale of the roughly $17 million that will be left on Robertson’s contract by the trade deadline, shame on them.

At exactly the right time and in the team’s weakest area, an enormous piece of good fortune may have fallen on the Nats — roughly the size of a 6-foot-5 bear.

Don’t abuse that good luck. Build on it.

For more by Thomas Boswell, visit washingtonpost.com/boswell.