The Emergence Of Gunnar Henderson

After making his Major League debut with the Baltimore Orioles last season, infielder Gunnar Henderson garnered a lot of praise. He was looked at as not only important to the 2023 Orioles but also to the organization’s future.

With that praise, came a strong prospect ranking. Coming into this season, Henderson was the consensus number-one prospect in all of baseball. But, now that he’s an everyday player in the big leagues, he has graduated from prospect status.

Through 349 plate appearances this season, Henderson has a .247/.341/.477 slash line with an above-league-average 125 wRC+ – the same wRC+ he posted in 132 big league plate appearances last season.

And while the infielder has enjoyed being Baltimore’s second-best hitter according to wRC+ and second-most valuable player according to fWAR – his 2.4 mark through play on July 23 trails the 2.5 mark of Adley Rustschman – it didn’t come without some early season bumps and bruises.

Early Season Struggles

Henderson was thought of as a potential American League Rookie of the Year candidate during spring training by many. But after starting the 2023 campaign without much success, he may no longer be the favorite for the award. That’s a conversation for another time, though.

In his 92 plate appearances between March and April, Henderson posted a 95 wRC+. The left-handed hitter continued his slightly below-league-average output in May, too, with a 99 wRC+.

Combining those numbers, Henderson entered the month of June hitting .201/.332/.370 with a 99 wRC+ in 184 plate appearances — far off the numbers many expected to see from the former second-round pick. But for a rookie, being around a league-average hitter is still a good thing.

One of the main reasons for Henderson’s “struggles” through the season’s first two months was his inability to hit four-seam fastballs – something he had plenty of success with in a small sample size last season.

In his 132 plate appearances in 2022, Henderson hit .371 against four-seamers. In March and April of this year, he hit .250 against that pitch type. Then, in May, Henderson hit way below that .250 mark with a .125 batting average against four-seamers.

While Henderson’s slash line through the end of May wasn’t great, it wasn’t because of a lack of quality contact. Between the months of March, April, and May, his hard-hit percentage was slightly above 47 percent. He also had a barrel percentage just north of 10%.

So when he put the ball in play, it was at good angles and with solid exit velocities. The problem, though, may have been his decreased contact numbers. On top of that, Henderson wasn’t swinging the bat as much, either.

In the Major Leagues last year, Henderson’s zone-contact rate was 81.5 percent, while his overall contact rate was 74.8 percent. He also had a 41.2 percent swing rate. And for the first two months of 2023, those numbers didn’t exactly match up to last year’s:

It’s clear that Henderson had some more swing-and-miss over the first two months of 2023 than he did in his short time in the big leagues at the end of last season.

He also wasn’t swinging as often — at least in March/April. That wasn’t all that bad, though. With a lowered swing rate, Henderson walked — a lot.

Last season, Henderson’s walk rate was 12.1 percent. In March and April of 2023 — when his swing percentage dropped almost four percentage points when compared to last year — his walk rate was an elite 18.5 percent. And, when his swing rate went back up in May, his walk rate came back down to 12 percent.

It wasn’t all bad for Henderson during the season’s first two months. However, there were clear areas where he could make adjustments and tap into the potential many people scouted him to have.

And since the start of June, Henderson has tapped into that potential.

The Turning Point

After his slow start to 2023, Henderson posted outstanding numbers in June.

His 171 wRC+ in June was tied for the 12th-highest number in the big leagues. His .640 slugging percentage was tied for seventh-best.

Altogether, Henderson hit at a .320/.354/.640 clip during the season’s third full month with 11 extra-base hits — six of which were home runs. He also had a 17.6 percent barrel rate in June with an astounding .400 batting average on balls in play.

Those excellent numbers were the result of some clear adjustments. Henderson started hitting fastballs again, while also swinging and making contact more often.

Henderson hit .476 against four-seamers in June and had a 64 percent hard-hit rate against them. He also started to swing the bat more as his swing rate increased to 48.7 percent. His contact percentage jumped, as well, to 76.7 percent.

As a result, his walk rate dipped to 5.1 percent. But, with a more aggressive approach, came more power.

All those numbers have come down a bit in July, but are still pretty good.

Between July 1 and July 23, Henderson put together a .267/.349/.533 slash line and a 141 wRC+. His swing rate decreased (43.6 percent), and as a result, his walk rate rebounded to 10.5 percent.

Overall Numbers and Statcast Data

Altogether, Henderson’s numbers through July 23 are not just good for a rookie, but they’re good for a big leaguer in general. They’re also similar to what he did in his short stint in the majors last year.

As discussed above, his wRC+ puts him as an above-league-average hitter (just like it did last year), while his walk percentage (12.0), OPS (.818), zone-contact percentage (81.4), overall contact percentage (73.7), and swing percentage (42.7) are all also comparable to last year.

For even more evidence of how good Henderson has been, here are some of his Statcast numbers:

Not only can Henderson hit, but he’s also been a fine defender while being a really good, and fast, base runner.

Most of his defensive innings have come at third base this year for the Orioles, but he has also played some shortstop.

His minus-one defensive runs saved and outs above average at third are okay, but he’s been better at short with three defensive runs saved and one out above average. Being able to play solid defense at multiple positions is just another check mark in the plus column for the young Orioles standout.

Henderson also has one of the stronger throwing arms in the game as his average arm strength of 91.2 mph sits in the 91st percentile among Major League defenders.

As he’s helped Baltimore both at the plate and in the field, Henderson’s also helped them on the base paths. His 28.7 feet-per-second sprint speed is in the 86th percentile among big leaguers, while he’s added three extra runs on the base paths according to Baseball Savant’s new runner runs metric.

In a sport where there’s a long list of young and talented players, Henderson is starting to make a case to join that list if he hasn’t already.