Fantasy Baseball Overvalued and Undervalued – Vladimir Guerrero Jr. Failing Fantasy Teams

As we inch towards the All-Star break and a chance to pause from setting our lineups every day or every week, we are starting to get a firmer glimpse of who is overvalued and undervalued based on the cost to acquire their services in drafts or auctions this spring. Some performances have exceeded expectations, while others have fallen behind. And time is running out to change their fortunes.

Value is an ever-changing target, but we do have a snapshot in time to look at how we valued these players in our drafts this spring. With about 85-88 games played for each team this season, it’s a good time to look at who is performing as we hoped and who is falling behind.

This weekly piece will look at the past few weeks of fantasy baseball performances to see who should be considered overvalued and undervalued going forward. When necessary, I will reference the Fantrax top 400 rotisserie rankings for the 2026 fantasy baseball season.

More great Fantasy Baseball Analysis: Fantasy Baseball Waiver Wire | Weekly SP Rankings | Pitching Streamers | Two-Start Pitchers | Lineup Analysis | MLB Injury Report | Rookie Report | Advanced Stats | Under the Radar | Overvalued & Undervalued | Bullpen Report

Fantasy Baseball’s Most Overvalued Players

(Stats are up to date as of June 29)

Vladimir Guerrero Jr. (1B – TOR)

It’s time to call a spade a spade in this unfortunate situation. Vladimir Guerrero Jr., who was scratched with a bad back on Tuesday, has simply been the most disappointing first baseman in MLB in 2026. After the 2024-2025 seasons, in which he hit .323/.396/.544 and .292/.381/.467, Guerrero is hitting .268/.347/.348 with fewer home runs (four) than stolen bases (six).

Now that Fernando Tatis Jr. has four home runs, it’s time to turn our attention to why Guerrero is struggling so much. He still has a 10% walk rate and a 10% strikeout rate, but a barrel rate (6.6%) that is half what it was last year. What’s leading to that? It looks like it’s primarily his chase rate.

Last season, Guerrero had a 21% chase rate on pitches outside the zone. This year, that number has ballooned to over 31%, which has led to a first-pitch strike rate of almost 61%. That number simply can’t continue if Guerrero wants his power to continue. His expected stats say some improvement could be ahead, but for now, Guerrero is the most disappointing healthy hitter in fantasy baseball.

Mickey Moniak (OF – COL)

Expectations for Moniak should be adjusted post-injury. His improved approach and power gains are reasons to hope in 2026, yet a hitter carrying a wOBA about 60 points above his xwOBA is usually riding some combination of good fortune and unsustainable results. Moniak’s expected statistics tell a story that his actual numbers don’t line up with his potential future production. His .367 wOBA has been backed by only a .309 xwOBA, one of the largest gaps among qualified hitters.

We are already seeing a decline in his recent return from injury, but Mickey Moniak is a strong negative regression candidate for the rest of the 2026 season. He has been one of the biggest breakout stories of the year in the first half, but his production has significantly outpaced what his Statcast numbers say he should be doing.

Moniak’s .550 slugging rate has already fallen by about 50 points from its peak and also sits well above his .444 expected slugging rate. This means some of his power production has been aided by variables that are unlikely to continue.

Fantasy Baseball’s Most Undervalued Players

Nico Hoerner (2B – CHC)

If you need the name of a player likely to significantly improve for the second half of 2026, Nico Hoerner has to be your man. Despite a 7% strikeout rate (second-best in MLB), Hoerner has just a .243/.319/342 line, including a 9.1% walk rate. However, all that is being dragged down by a .252 BABIP, which is a full 50 points below his career average.

That number is one of the 20 lowest BABIPs in the league right now, and it’s something that just has not improved over the first half of the season. All of Hoerner’s other stats are there. His line drives and fly balls are up. His ground balls are down. Hoerner’s hard-hit rate is just a smidge lower than last season’s. His bat speed is identical, as is his contact rate.

This is a player to trade for in the second half, and not someone you are looking to sell for 70 cents on the dollar. If nothing else, the runs and steals should ramp up this summer. With a disappointing first three months, he has 35 runs and 12 steals. Imagine if he starts to hit well for three months. Those numbers would be his floor.

Ryan O’Hearn (1B/OF – PIT)

In his first season in Pittsburgh, Ryan O’Hearn has quietly become one of the biggest fantasy baseball values of the 2026 season, even with some time missed due to injury. He has transformed into a legitimate middle-of-the-order power contributor. So far in just70 games, O’Hearn has posted a .288/.343/.477 slash line with 13 home runs, 51 RBI, 40 runs scored, and a stolen base.

That performance gives him an impressive .820 OPS and a 124 wRC+, all numbers that are the best of his career. He has bounced around several times in his career (three teams in the last two seasons), but he’s found a place to hit in Pittsburgh, despite their cavernous park.

The reason fantasy managers have overlooked him is that Bauers entered the year with a career .751 OPS and never fully developed into the power hitter he was expected to be when he was drafted in 2014. However, his 2026 production has shown a completely different hitter. He is getting on base, driving the ball hard (43.6% hard-hit rate), and contributing across multiple categories. His combination of power and patience have made him far more valuable than his spring draft slot suggested.