Is Matt Wallner's Playoff Roster Spot in Jeopardy Amidst Slump?

A young player's first full season in Major League Baseball is often a story of ups and downs. It is a yin-and-yang relationship where the highest of highs tend to get followed up by the lowest of lows. That phenomenon is currently happening to Twins rookie outfielder Matt Wallner.

Wallner, 25, made his Major League debut for the Twins in mid-September of the 2022 season, hitting .228/.323/.386 (.709) with 13 hits, two home runs, and a 103 wRC+ over 65 plate appearances. The toolsy outfielder was impressive during his first cup of coffee at the Major League level, but making meaningful conclusions over such a short sample size would be malpractice. 

The early portion of the 2023 season saw him making multiple trips east and west along I-94. Wallner started the 2023 season with the St. Paul Saints and was eventually called up by the Twins on April 9 to replace a then-injured Max Kepler, who was placed on the 10-day IL on April 8. He played in six games for the Twins and couldn't generate a hit in 11 plate appearances before getting optioned back over to St. Paul on April 15. The Twins then recalled Wallner a second time on May 23, and he performed exceptionally well, hitting .636/.714/1.000 (1.714) with seven hits, one home run, and a 364 wRC+ over 14 plate appearances.

Nevertheless, he was sent over to the 651 once again. 

Over the next month and a half, Wallner hit well enough that most Twins fans wondered why he wasn't getting an opportunity over then-struggling left-handed hitting corner outfielders Trevor Larnach, Joey Gallo, and Max Kepler. Finally, on July 17, Wallner again got promoted from Triple-A St. Paul and has been with the Major League club ever since.

Wallner started his third stint off hot, hitting .238/.333/.571 (.904) with 15 hits, six home runs, and a well-above-league average wRC+ of 145 from July 17 to August 6. He capped off this hot stretch with a walk-off home run off Arizona Diamondbacks closer Paul Sewald.

The Twins, their fans, and Wallner himself were riding a high and reasonably so. A young, highly-touted prospect finally got an opportunity to contribute to his home-state team and was performing incredibly well. Why wouldn't everyone celebrate Unfortunately, Wallner's walk-off against the Diamondbacks marked the beginning of a downward spiral that has many questioning his short and long-term future with the Twins. 

To put Wallner's struggles into perspective, here are his numbers since August 7:

• Wallner - .172/.308/.391 (.699), 104 PA, 15 hits, two doubles, one triple, five home runs, 10.6% BB%, 35.6% K%, .218 ISO, .222 BABIP, 96 wRC+

Wallner hasn't performed terribly in this stretch, but it is arguably the worst month-long stretch of his career. To condense the sample size provided even more, here are Wallner's numbers since September 1:

• Wallner - .154/.333/.269 (.602), 33 PA, four hits, one home run, 21.2% BB%, 36.4% K%, .115 ISO, .231 BABIP, 81 wRC+

Offensively, he is struggling immensely as of late, and his ballooned K% of 36.4% and exaggerated swing-and-miss profile have many Twins fans derogatorily dubbing Wallner as a young version of Gallo. 

So, what is happening to Wallner? Let's take a look. 

Increased Swing-and-Miss Rate
To begin, Wallner swings and misses at a lot of pitches, and while this isn't an inherently bad thing (see: Edouard Julien), the amount in which Wallner swings and misses on pitches is alarming. 

The best way to illustrate Wallner's swing-and-miss problem is through using the batting statistic titled Whiff%, which is a statistic that divides a hitter's total number of swings and misses by their total number of swings. 

Wallner currently possesses a Whiff% of 37.1% on fastballs, 43.1% on breaking balls, and 28.1% on off-speed pitches. Combined, Wallner's overall Whiff% sits at 37.5%.

To go back to the Gallo comparison, Gallo currently possesses a Whiff% of 37.1% on fastballs, 50.6% on breaking balls, and 58.4% on offspeed pitches. 

Nobody in modern baseball has as high of a Whiff% of Gallo and his 1st-percentile Whiff%, but Wallner is alarmingly close, particularly on fastballs, where he has an identical Whiff% as Gallo of 37.1%.

Wallner has struggled hitting fastballs as of late, but there is reason to believe he can quickly overcome this specific shortcoming at a relatively quick pace.

Hitters tend to be able to make the appropriate adjustments on fastballs as they typically need to make slight revisions to both their timing and swing paths. Wallner should be able to make the adjustments, and while it likely will not happen this season, an offseason of tinkering with his swing should help him catch up to fastballs at a sustainable rate.

What is alarming is that Wallner has a Whiff% of 43.1% on breaking balls. Hitters are less likely to make quick and relatively simple adjustments and suddenly be able to hit breaking balls like they can with fastballs. There is much more nuance to hitting breaking balls, and an extreme overhaul of Wallner's swing may be necessary.

While this overhaul will not happen this late in the season, it is something to monitor this upcoming offseason, and it will be interesting to see how Wallner's stance and swing plane look next Spring Training.

Until then, all the Twins can do is work with the player they have now. And while teams will continue to attack Wallner with both fastballs and breaking balls, there is reason to believe he can make the necessary short-term adjustments, particularly with fastballs, to help him perform more like the player he was in late July and early August.

Wallner may need to simplify his stance and shorten his swing to get the most out of his at-bats for the rest of the season, and that may come at the expense of some power, but that is a trade-off that Wallner and the Twins would likely accept with open arms for the time being.

Are Wallner's Struggles Simply Him Being a Young Player?
Young players struggling, especially those of the power-hitting variety, is in no way an uncommon phenomenon as other young Twins hitters in Trevor Larnach, Gilberto Celestino, Ryan Jeffers, Royce Lewis, Alex Kirilloff, Willi Castro, and the previously mentioned Julien either have or currently are undergoing offensive struggles of their own.

What separates young players who can stay at the Major League level (i.e., Kirilloff and Lewis) and those who end up stuck in the constant limbo of being a Quad-A player (i.e., Celestino and Larnach) is whether they can make the necessary adjustments needed to be able to hit Major League pitching at a satisfactory rate. 

Wallner may be enduring the same struggles that every young player does, and he may be able to turn the corner and become a consistent contributor for the Twins for seasons to come. Unfortunately, the timing of his struggles at the plate couldn't have happened at a more inopportune time. 

The Twins are all but set to make their first postseason appearance since 2020, and the complicated judgment of who makes the playoff roster and who gets left off will soon need to be made by Twins decision-makers. 

A month ago, it seemed like Wallner was a near lock to make the roster, but that once obvious decision has become much cloudier as Wallner continues to struggle.

Should Wallner Make the Twins Playoff Roster?
To answer this question, we must first examine how the Twins outfield will likely look come playoff time.

Currently, the Twins outfield options include Wallner, Kepler, Castro, Kirilloff, Celestino, Jordan Luplow, and Andrew Stevenson. Other potential outfield options include players on the injured list: Gallo, Nick Gordon, Byron Buxton, and Michael A. Taylor.

Prospect Austin Martin is another option, but the Twins adding him to the 40-man roster and throwing him into action in the middle of a pennant race feels highly unlikely. 

Looking at the Twins' current outfield situation, Kepler, Castro, Kirilloff, and Luplow feel like locks to make the playoff roster. Luplow is strictly a right-handed platoon player, but his archetype is all too valuable in the playoffs. Celestino is only on the roster to take up space until Jorge Polanco returns from the bereavement list, and Stevenson could make the playoff roster, but he feels like a long shot.

It always takes work to get a read on where players are regarding their health. Yet, when discussing Gallo, Buxton, Gordon, and Taylor, it feels like Taylor is a lock to make the playoff roster, while the potentially soon-to-return Gallo and Gordon could make it if injuries pile up. But unless that happens, Gordon and Gallo also feel like long shots. 

Buxton is a unique case; there is no reason to speculate until the Twins provide official updates. 

As things stand, Wallner is likely on track to make the playoff roster alongside fellow outfield options Kepler, Castro, Kirilloff, Luplow, and Taylor. 

If Wallner continues to struggle and a veteran like Buxton, Gallo, or Gordon returns from the injured list and produces, or if Stevenson begins to produce more offensively, Wallner's status could change. 

Come Game One of the Wild Card Series, the Twins will likely start Taylor in center field and Kepler in right field. Who will start in left field is still open for the taking, and if Wallner continues to struggle, don't be surprised if Castro, Luplow, or Kirilloff start in left field come October 3.

Wallner's first stretch of prolonged struggles were expected, but the timing could not have been more unfortunate for the young Minnesota native.

What do you make of Wallner's struggles? Does he deserve to make the Twins playoff roster? Comment below.