MLB Prospect Rankings: Top 10 Third Basemen

Let's knock off another position in our breakdown of top-100 MLB prospects, and top-10 players at each spot. Here, we'll go over third basemen.

We have looked at first basemen, catchers, right-handed pitchers and left-handed pitchers so far. Keep checking back for more.

There's no primary third basemen in the top 100, so we will just be looking at the top-10 list at the position. Texas' Sebastian Walcott and Chicago White Sox' Caleb Bonemer are in the top 100, but are shortstops before third basemen.

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Andrew Fischer - Milwaukee Brewers

Fischer is the top third baseman, and just missed the top 100. He's 21 years old and was drafted 20th overall last summer. Fischer has a 2027 ETA.

In 19 games at Triple-A, Fischer had a .311 average and .402 on-base percentage last season. He's known most for his bat, and at his age, he could be a quick riser. 

It still will probably be until 2027 until we see him in the big leagues, but he's a name to keep in mind down the line. He is a better dynasty asset at this point.

Jacob Reimer - New York Mets

Reimer is 21 years old and has a 2026 ETA. He was a fourth-round pick in 2022.

He has been in the minor leagues over parts of four years, logging 256 games so far. Reimer has a .269 average and .386 OBP.

He can also play first base, so he has a couple ways to make it to the big leagues. Reimer will need to earn his spot in the MLB, and keep delivering when there to stick, as the Mets have big-time players all over the place, and will be competing for the NL's top spot.

Hao-Yu Lee - Detroit Tigers

Lee is 22 years old and has a 2026 ETA. He was signed originally by Philadelphia back in 2021.

He's played in 376 minor league games over five years, making it up to Triple-A. Lee has a .272 average and .361 OBP so far.

Lee can also play second base, so there's a couple ways for him to reach the big leagues as well. He probably needs to improve his numbers in AAA before he gets called up, but a big spring could force the team's hand.

Tommy White - Athletics

White is another corner infielder option, so he too can play first base. He's 22 years old, was the 40th overall pick in 2024 and has a 2027 ETA.

In two minor league years, he's played 118 games. White has a .263 average and .327 OBP so far.

He's got some minor league seasoning ahead of him yet, but after a solid showing in Double-A, he could get an MLB call up even at the end of this coming year. Keep an eye on him.

Mikey Romero - Boston Red Sox

Romero can play second base too, so that works in his favor. He's 22 years old and has a 2026 ETA. Romero was a first-round pick in 2022.

He has a .255 average and .309 OBP over 242 minor league games in four years. 

Romero made it up to Triple-A, but probably needs a little more time in the minor leagues before he gets an MLB call up.

Gino Groover - Arizona Diamondbacks

Groover is 23 years old and has a 2026 ETA as well. He was a second-round pick back in 2023.

Groover has a .297 average and .384 OBP over 211 minor league games, so he definitely is a prospect that sticks out to me plenty. 

He's only made it to Double-A so far, so he probably has a little more time in the minor leagues before he'd get a big league call up. Groover is definitely on my radar though for whenever he gets to the MLB.

Juan Sanchez - Toronto Blue Jays

Sanchez can also play a couple positions, with his second one being shortstop. He's only 18 years old. Sanchez signed with Toronto in early 2025.

Sanchez posted a .341 average and .439 OBP over 56 games in rookie ball, so he's off to a terrific start, but also has several more years to go before we're discussing him as a big league call up.

Sanchez is a dynasty asset to stash, especially in deeper leagues. We'll see if he can keep excelling, and eventually works his way into the overall top 100.

Chase Harlan - Los Angeles Dodgers

Harlan is just 19 years old and has a 2028 ETA. He was a third-round pick in 2024 and excelled in his lone minor league season so far.

He made it to Single-A, posting a .269 average and .357 OBP over 68 total games last season. 

The Dodgers have a good minor league system, so as long as he sticks around, he could develop into something special. We'll see if he can excel and force his way to the big leagues sooner than 2028.

Brock Wilken - Milwaukee Brewers

Wilken is 23 years old and has a 2026 ETA. He was the team's first-round pick in 2023.

Wilken has just a .225 average, but a .358 OBP over 235 minor league games in three years so far.

He's topped out at Double-A, so Wilken has some more minor league seasoning ahead, but a 2026 call up is doable, especially if Milwaukee is ever dealing with injuries at third base.

Parks Harber - San Francisco Giants

Harber is another option at first base as well. He's 24 years old but has a 2027 ETA. Harber was signed as an undrafted free agent by the Yankees in 2024.

Harber has a .312 average and .413 OBP over 102 minor league games over two years, and has topped out at High-A.

He could get to the big leagues sooner if he keeps raking at the plate. We'll see if the Giants push him, or ease him along.