It was a phenomenal turnaround for outfielder Spencer Nivens in 2024. The 2023 fifth-round pick out of Missouri State struggled to open the year. Many of those early struggles centered around injury. Nivens suffered a hamstring injury running for a fly ball in the outfield. That injury went on to sideline Nivens for three weeks. Even after his return, however, the results weren’t great. It all resulted in a pedestrian .178/.300/.297 slash line through the season’s first half. Nivens didn’t hit for power (.119 ISO) and it looked at the time that the 22-year-old had a ways to go in his development.

Then, the season’s second half changed the entire narrative. The Royals’ outfield prospect exploded in the second half. From July 15 on, he hit for a 196 wRC+. His ISO ballooned to .359 in that span with 16 home runs in just 45 games. Now, with the full season behind us, Nivens quickly went from a struggling prospect to a name on the rise in the farm system. He won’t likely be Aaron Judge-level of good forever, but clearly, there’s something there for the Royals. The improvements seem clear after looking at some early season at-bats and comparing them to second-half swings.

Tweaks after a hamstring upgraded the performance at the plate for Nivens

Nivens made some noticeable tweaks when comparing his season’s first and second half. On the left below is his stance from May, compared to his stance in August on the right. Most of the adjustments are in his hands. Much of the early season saw Nivens keep his hands and elbows high. It wasn’t a very relaxed stance and that tension looked to impact timing and hard-hit ability.

The more relaxed stance at the plate helped Nivens in many ways, but timing seemed most impacted. His strikeout rate dropped four percent over his hot stretch at the end of the year. He also raised his average by nearly 150 points. As Nivens moved into his swing mechanics, much of the early season saw him drop his front shoulder. On the left below, you see as much. Nivens dips his front shoulder as he moves into his leg kick. The timing issues from his tense hands gave way to an out-of-center upper half.

By the end of the season on the right, Nivens was keeping his upper half more square. You see on the right his front shoulder staying up. That squared upper half helped Nivens with timing while allowing him to hit for more power in the process. Instead of reaching and trying to catch up, Nivens was more relaxed at the plate and able to swing with conviction. Those improvements allowed Nivens to tighten up his lower half as well.

This is where the hamstring injury may have continued to hamper Nivens some upon his return. On the left is again the early season from Nivens. He brought up his kick leg, but not nearly as firmly as he did to end the year. By August, the front knee was coming up closer to hip level than thigh level as it is on the right. That slight shift allowed Nivens to swing with more power. A higher leg kick allowed Nivens to swing through the baseball with more explosiveness. Pairing that bottom half tweak with some clean-up in his timing and upper half resulted in a true best-case breakout for Nivens over the season’s back half.

More explosiveness has Spencer Nivens poised to become the Royals left-fielder of the future

The tweaks above were the foundation, but they all came together in the explosiveness of Nivens’ swing. He looked to open his hips too early at times. This meant most of his swing power came from Nivens’ upper half — his arms, shoulders, and wrists. Opening the hips too early zaps a notable amount of power and explosiveness.

In the second half, the hip extension for Nivens was noticeably later. Instead of opening too early, Nivens was holding his posture and exploding through the baseball. That shift came through in the results and was a clear driving force behind his second-half power explosion.

All of these in-season adjustments helped Nivens to truly break out in 2024. Even his season-long statline looks solid, despite how poor the early season went. Heading into 2025, he’ll be on track to debut in Double-A as a 23-year-old. The trend upward in zone-contact rate was great to see from Nivens and stems greatly from those improvements outlined above. Another full offseason with the organization — and hopefully a healthy start to next season — could continue raising the stock for Nivens into one of the organization’s best hitting prospects.

It remains a very pull-happy profile — Nivens finished the year with a 52.8% pull rate. Despite that, there’s enough success elsewhere that the pull rate should help Nivens more than it hinders him. The overall profile reminds me of a left-handed version of Austin Hays. Hays, since becoming a full-time big leaguer in 2021, has slashed .260/.312/.433 over 505 MLB games. He has 59 home runs and a 108 OPS+ in that span. Nivens walks more currently than Hays ever has, but the Royals tend to steer hitters toward more of a contact approach than taking walks. For that reason, I expect the walk rate will continue to trend downward as Nivens continues tweaking his swing and finding success.

In the end-of-year update, Nivens moved into the top ten prospects at number seven. It’s probably more of an average hit tool long-term, but the power looks above average and the rest of Nivens’ tools are well-rounded. There isn’t a glaring weakness anywhere in his game. With a strong 2025, it’s likely time to start considering him the left-fielder of the future for Kansas City.