Article: The Slump of the Guerrero

[Leo Morgenstern]

Come along and count with me: 

• Zero: The number of home runs Vladimir Guerrero Jr. hit over the final two weeks of the regular season.
• One: The digit each of his triple slash stats started with in that time (.164/.193/.182).
• Two: His wRC+.
• Three: That's how many double plays he grounded into, tied for the most in the league.
• Four: And that's how many times he came around to score in 57 trips to the plate.
• ...
• ...
• Nine hundred forty-two: The number of players with a higher FanGraphs WAR than Guerrero over those two weeks.

Vladdy was hotter than hot when September kicked off. From the All-Star break through Saturday, September 13, his 1.040 OPS, 188 wRC+, and .420 xwOBA all ranked third among qualified AL hitters. Even a brief injury scare in mid-August couldn't slow him down. 

Then, from September 14 through the end of the regular season, the Blue Jays' superstar all of a sudden went ice cold. Ups and downs are typical for any player, and Guerrero is no exception. But this was no ordinary down. 

Over his final 14 games, Guerrero produced a 2 wRC+. That means his production was 98% worse than that of a league-average hitter. The following graph shows his wRC+ in every 14-game stretch of his career. You'll see plenty of high points and plenty of low points. You'll also see he's never had a low point quite this low:

The second-lowest point you'll see on that graph is an 8 wRC+ from April 26 to May 10. That's only an 11-game stretch, because Guerrero had only played 11 career games to that point. He had just turned 20 years old.

So, his second-lowest wRC+ in an actual 14-game stretch was 30. Thirty. His wRC+ in his last 14 games is 2. Two. That's a 28-point difference, the same as the difference between Ernie Clement (98 wRC+, .711 OPS) and Andrés Giménez (70 wRC+, .598 OPS). Think about that: The gap in production between Guerrero's last 14 games and his previous worst 14-game stretch is the same as the gap in production between 2025 Clement and 2025 Giménez. That's huge. 

Vladdy also ranked last among all players (pitchers and hitters) in FanGraphs WAR from Sept. 14-28, and his -0.6 fWAR in that time was also his lowest in any 14-game span of his career. It's not hyperbole to say we've never seen him look worse.

The good news is that none of this ended up hurting the Blue Jays. They still went 8-6 (.571) in their final 14 games, right in line with their 86-62 (.581) performance over their first 148. More to the point, they still won the AL East, securing a first-round bye and home field advantage through at least the ALCS. Sure, a little more production from Guerrero might have saved the fanbase a whole lot of nail-biting over the final days of the season. But knowing how everything worked out, would you really have wanted it any other way?

If you're the pessimistic sort, I suppose you might be worried about Guerrero's struggles carrying over into October. The Jays survived his slump in September, but now the stakes are higher, and the competition will be harder.

Yet, as an optimist, I implore you to put more stock in Guerrero's full-season 137 wRC+ (and his matching career 137 wRC+) than his disappointing numbers from the very end of the season. I encourage you to remember that even during his slump, his strong contract skills and elite bat speed remained unchanged. Two weeks – any two weeks – make for a tiny sample, and stats from tiny samples aren't to be trusted, no matter how recent or dramatic they might be.

Vladimir Guerrero Jr. is entering the postseason coming off the worst two weeks of his career. That's a true story, and it's one worth telling. It's not, however, any reason to worry about his performance going forward. 

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