Reviewing the Rookie Hitters — Through May 14, 2023

Yesterday, I reviewed four rookie hitters that were former top prospects. Today, let’s continue with the rookie hitter reviews, this time mixing in some surprising top performers with additional former top prospects.

It’s only been 46 PAs, but Dominic Fletcher has hit well enough so far to earn a starting outfield job for the Diamondbacks and generate interest from fantasy owners, as he was just bought in LABR Mixed with three teams bidding on him (I was not one of those teams). Fletcher wasn’t ranked, nor named in the latest team top prospect report, so he’s one of those types of pickups that come out of nowhere to win fantasy team leagues. He’s shown power off and on in the minors, with strong home run and overall power at Double-A in 2022 over a small sample, but the power disappeared when promoted to Triple-A, especially his over-the-fence power, as his HR/FB rate slid to just 5%. His overall power rebounded during his second tour of Triple-A this year, though his HR/FB rate was just mediocre.

Nevertheless, a strong .430 wOBA earned him a promotion to the Majors, and he has posted an absurd .488 wOBA since. He’s done it with excellent contact ability (7.5% SwStk%) and his best power show yet (.262 ISO), but this looks mostly like smoke and mirrors. He’s sporting a crazy .485 BABIP and his .345 xwOBA, while still solid enough, is significantly below his actual mark. Fantasy owners picking him up now should be reminded that previous stats recorded before being active on your team do not get added to your season stat total! With little speed and middling power, he looks like the definition of a replacement level hitter in a shallow league. Just as fast as he was picked up, he’ll likely be dropped right back into the free agent pool within the next couple of weeks.

Speaking of coming out of nowhere, James Outman was ranked 27th in this year’s Dodgers prospect report and is already 26-years-old. Now the Dodgers starting center fielder, Outman has shown excellent power throughout his minor league career, only once posting a sub-.200 ISO. He also posted HR/FB rates over 20% during his last three stints, from Double-A through Triple-A. He even steals bases too, swiping 20+ in 2019 and 2021, and then another 13 last year. Oh, and he has typically walked at a double digit rate, giving him extra OBP league format value. Finally, a history of high BABIP marks suggest he might not kill you in batting average, despite the potential for a high strikeout rate.

I’m not sure what’s not to like here and feel like maybe he was undervalued as a prospect. So far, he’s performing essentially how his minor league performance suggested he was capable of. The only real concern is a high .368 BABIP, which is quite difficult to pull off given his combination of a low LD%, high FB%, and high IFFB%. With a strikeout rate over 30%, his batting average over the rest of the season could tumble, which could lose him some playing time. Everything else looks pretty good though, but it couldn’t hurt to offer him around in a potential sell high if you own him.

Triston Casas was the game’s 28th ranked prospect heading into the season, with exceptional power grades, including 55/70 Game Power and 70/70 Raw Power scores. That’s interesting, because he has never actually displayed such elite power in the minors, as his HR/FB rate has topped out at just 16.9% over a reasonable sample size, while his ISO peaked at just .218. Decent enough numbers for sure, but marks that certainly don’t match his scouting grades. With a high walk rate, he looked to be another who would enjoy a significant boost in value in OBP leagues, while potentially being replacement level in shallower leagues that count batting average.

So far, that is what has happened. He’s currently hitting just below the Mendoza Line (sub-.200 batting average), while his OBP is perfectly acceptable at .328. That’s thanks to a .221 BABIP, which Statcast calculates as being marginally lower than he’s deserving of. His 16.1% HR/FB rate and .183 ISO are right in line with his minor league rates. Overall, he’s performance within the range of possibilities and it’s anyone’s guess if he’ll ever actually post power numbers that match his high power scouting grades.

After a cup of coffee last year, Josh Jung headed into the season as the league’s 30th ranked prospect. Big power was his potential, but a decline in plate discipline metrics at Triple-A last year that carried over to his MLB debut was a concern. Unfortunately, it’s been more of the same this year, as he has walked just 4.9% of the time, while striking out just over 30% of the time. He has flip-flopped his batted ball profile and become a fly ball hitter again, taking full advantage of his 17.4% HR/FB rate, and that actually hasn’t yet hurt his BABIP. His strikeout rate is going to be the key here, but right now, all his result metrics appear to be around where they should be. With little speed, it’s all about the power, with the hope that his batting average doesn’t fall too far.