Here are the Top 10 1B prospects for 2023

January 19th, 2023

MLB Pipeline will reveal its 2023 Top 100 Prospects list at 7 p.m. ET on Thursday, Jan. 26, with a one-hour show on MLB Network and Leading up to the release of the Top 100, we'll examine baseball's top 10 prospects at each position.

And now we turn our attention to some real boppers -- the first basemen.

Red Sox slugger Triston Casas ranked No. 2 on last year’s preseason list, finished 2022 atop the 1B rankings and finds himself there again to begin the 2023 campaign. Having played more games at first last year than at his drafted position (catcher), A’s prospect Tyler Soderstrom joins a first-base preseason list for the first time and slides in behind Casas in the second spot. Rays breakout star Kyle Manzardo jumped seven spots from last year’s spring list to join the 2023 version of the Big Three in this category.

Based on this ranking, some clubs could have fun position battles on their hands in the future. The Red Sox, A’s, Rays and Rockies all have two first basemen each on our Top 10. Oakland’s pair of Soderstrom and Jordan Diaz, in particular, both have ETAs of this upcoming season.

The Top 10 (ETA)
1. Triston Casas, Red Sox (2023)
2. Tyler Soderstrom, Athletics (2023)
3. Kyle Manzardo, Rays (2023)
4. Matt Mervis, Cubs (2023)
5. Jordan Diaz, Athletics (2023)
6. Michael Toglia, Rockies (2023)
7. Grant Lavigne, Rockies (2024)
8. Ivan Melendez, D-backs (2025)
9. Xavier Isaac, Rays (2026)
10. Niko Kavadas, Red Sox (2024)
Complete list »

Top 10 prospects by position:
RHP | LHP | C | 1B | 2B | 3B | SS | OF

Top tools

Hit: Manzardo (65)
The 2021 second-rounder led Minor League first basemen (min. 300 PA) with a .327 average last season between High-A and Double-A in his first taste of full-season play. Manzardo was already credited with an impressive knowledge of the zone and quality swing decisions during his time at Washington State, and those skills translated instantly to the pros. While he may lack the stellar exit velocities of others on this list, he’s able to find the barrel in other ways, leading to the belief he could be a .300 hitter over multiple seasons in The Show.

Power: Casas (65)
Take a look at Casas’ 6-foot-4, 252-pound frame, and you can tell immediately where the power projection comes from. Projection remains an optimal word because the left-handed slugger’s focus has been on developing an all-fields hitting approach in the early stages of his career. That’s good for the long term but has kept him from slugging above. 500 for a full-season club. Now that he’s 23 and Major League-ready, Casas’ power should pop at Fenway this year, just in time to lock in his place as Boston’s long-term cornerstone at first. Notably, five of his 11 hits with the big club left the yard last year.

Run: Diaz, Toglia (45)
You aren’t going to find many burners at this position, or else they would be playing elsewhere. Toglia’s relatively quick feet make him a Gold Glove-caliber defender at first and got him some looks in right field in the Majors last year. Similarly, Diaz made the majority of his MLB starts at second base because Mark Kotsay and Co. wanted to see how his speed would translate to a more athletic position. Both still project best at first, but to their credit, they have enough athleticism to move around.

Arm: Casas, Mervis (60)
Casas was initially drafted as a third baseman because of his strong arm, and he threw in the low-90s during his days playing high school ball in Florida. Mervis threw 59 innings over his four years at Duke while sporting a heater around the same velo and a low-80s slider. The pair may not use their cannons as much as they used to, but any overly aggressive baserunner might want to heed this warning if they see either first baseman with the ball in their hands.

Field: Toglia (65)
We named Toglia to our All-Defense Prospect Team last week, and it was a fairly easy call. Toglia reacts well on balls hit hard toward first and shows the necessary soft hands to scoop rockets off the bat or throws from anywhere on the dirt. His stellar glovework gives him a decent floor, and it wouldn’t shock to see him bring some golden hardware to Denver within the next three years.


Highest ceiling: Casas
Casas is the only member of this list with four tools that grade out at least above-average, making him the most well-rounded first-base prospect in the game today. He should hit for both average and power, and even on days when he doesn’t do that, he can still impact the game defensively. All of that is why Boston has cleared out space to make Casas its Opening Day first baseman in March.

Highest floor: Manzardo
There’s little doubt now that the Tampa Bay prospect will produce solid averages and on-base percentages. Questions about his overall slugging ability temper expectations of his future value, but guys with his skills will always find their way into a Major League lineup. Anything close to a reproduction of his 2022 season, and he’ll be in St. Petersburg by the fall.

Rookie of the Year candidate: Casas
Eric Hosmer was designated for assignment. Bobby Dalbec’s days as a starter appear numbered. Casas got 27 games in the Majors last year, and though his .197 average in that time doesn’t stand out, he still drove the ball well to all fields in a sign that his advanced approach will play in the bigs. The ceiling is there. The potential playing time is there. Everything is lining up for a Casas run at ROY.

Highest riser and humblest beginning: Mervis
Never mind the 1B list, Mervis wasn’t even ranked among the Cubs’ Top 30 prospects at the end of the 2021 season. The former Blue Devil was signed by the Cubs for $20,000 as a nondrafted free agent in 2020 and then produced just a .676 OPS in 69 Single-A games in his first full season a year later. Then, he exploded for 36 homers (tied for third-most in the Minors) across three levels in 2022 and heads into his age-25 season competing for a spot in Wrigley. Talk about a quick turnaround.

Most to prove: Isaac
The Rays shocked the industry by selecting North Carolina high-schooler Isaac with the 29th overall pick last July. Tampa Bay decision-makers noted how much they loved Isaac’s ability to generate bat speed and high exit velocities, but it still seemed like a reach for a player listed at No. 113 in MLB Pipeline’s Draft rankings. It may take years before Isaac lives up to his parent club’s hopes from that Draft slot, but his development in the meantime will be carefully watched by many.

Keep an eye on: Robert Perez Jr., Mariners
After previously topping out at 15 homers, Perez broke out with a career-best 27 blasts in 127 games at Single-A and High-A last season. He was somehow even more dominant away from the California League with a .342/.477/.583 line in his 53 contests with High-A Everett. Seattle tested the 22-year-old further with an assignment to the Arizona Fall League, and he responded there with a .753 OPS in 19 games and the circuit’s Home Run Derby crown. His improvements to get to his above-average power potential seem real but will be tested again when he reaches the upper levels this summer.