Fantasy Baseball Prospect Risers - Rookies to Stash and Top Performers for Week 5

April 26, 2026

Jeremy's top fantasy baseball prospect risers, breakouts with big upside for Week 5 of 2026. He analyzes top MLB rookies and call-ups to stash who are surging.

Welcome to the Week 5 edition of the top prospect performers. In this weekly piece, we'll look at prospects who are performing exceptionally well as of late who could be worth stashing or monitoring for fantasy purposes. Now that we're nearly a month into the season, it's becoming clear that some young players have completely figured things out at their current minor league level.

We've seen a flurry of promotions this season, including Konnor Griffin, Noah Schultz, Sam Antonacci, and most recently, Payton Tolle. Tolle absolutely dominated the Yankees in his 2026 debut with the big league club, striking out 11 batters over six one-run innings. That type of upside is typically hard to find on the waiver wire, which shows just how important it is to be up to date on the recent news regarding top prospects.

If you missed out on Tolle and the others, don't worry, as there are still plenty more on their way. This week, we'll take a look at one high-performing outfielder who could be ready for a promotion any day now, along with two extremely high-upside prospects who are a bit farther out from a potential debut. Without further ado, let's get into it.

Ryan Waldschmidt, OF, Arizona Diamondbacks

Diamondbacks No. 1, Overall No. 51

Ryan Waldschmidt is one of the prospects with the most potential 2026 impact that I haven’t covered in this piece yet this year. That was mainly because many other prospects got off to a hotter start, but that’s not to say that Waldschmidt has been disappointing in Triple-A.

In fact, he currently has a .330/.441/.538 slash line with two home runs, 15 RBI, 23 runs, and four stolen bases. He’s been especially good as of late, with at least one hit in 12 of his last 14 games, with six of them being multi-hit performances. 

Ryan Waldschmidt is an extra-base hit machine 😤

He notches his 8️⃣th extra base hit of the season. pic.twitter.com/EXlMjaOIcZ

— Reno Aces (@Aces) April 11, 2026

He’s always excelled at getting on base throughout his minor league career, as in 2025 he slashed .289/.419/.473 with 18 home runs, 78 RBI, 114 runs, and 29 steals in 134 games.

While he’s not an elite slugger necessarily, he did post a max exit velocity of over 115 mph in spring training this year, so the pop is there. He’s not the type of outlier prospect who will come up and threaten 40 homers or 60 steals, but his elite on-base skills mixed with decent power and speed could make him a valuable fantasy asset if he earns a promotion. 

The 23-year-old can play all three outfield positions, which helps his chances of finding playing time at the major league level. Even with Lourdes Gurriel Jr. recently returning from the injured list, the Diamondbacks are far from having a logjam of elite major league talent.

They currently have Alek Thomas and Jorge Barrosa splitting time in the outfield, with Jose Fernandez seeing a lot of DH appearances. There are definitely ways for Arizona to work in Waldschmidt consistently, and it’s not crazy to think that he's already a better player than Thomas.

Verdict: Stash in NL-Only Leagues

Theo Gillen, OF, Tampa Bay Rays

Rays No. 1, Overall No. 66

Theo Gillen isn’t the typical type of prospect featured here, as he is still currently in High-A. Even though he doesn’t have much value in redraft leagues for 2026, he deserves recognition as one of the fastest-growing fantasy assets in dynasty and keeper leagues. 

So far in 2026, he is slashing .333/.422/.846 with five home runs, 14 RBI, 14 runs, and three steals. He has been tearing the cover off the ball as of late, with back-to-back two-homer games on April 11th and April 12th, with five total homers in his past five games.

While it’s generally not super helpful to analyze a handful of games at High-A to determine someone’s value as a prospect, this recent power spike is very notable for the youngster. 

Theo Gillen goes deep in his return to the @BGHotRods lineup ⚡️

Each of the past 5 hits for @RaysBaseball's No. 1 prospect have been home runs, giving him a 1.226 OPS at High-A. pic.twitter.com/b7PFXoO6wk

— MLB Pipeline (@MLBPipeline) April 22, 2026

The 20-year-old already has matched his home run total from 2025, when he hit .267 with five homers and 36 steals in 73 games at Low-A. He was the 18th overall pick in the 2024 draft, with many hoping he’d grow into some more power eventually after he impressed with great contact skills and speed. He also walked at a 19.8% clip last season, showing excellent plate discipline. 

If he keeps up his recent display of power, he’d be a true five-category standout who could quickly become one of the most highly regarded prospects in fantasy.

If you play in a dynasty league or a league that involves keeping prospects, check to see if you can get Gillen for cheap before his value skyrockets. If everything continues to go smoothly, he could push for a debut at some point in 2027. 

Verdict: Rising Asset in Dynasty Leagues

Kade Anderson, SP, Seattle Mariners

Mariners No. 2, Overall No. 17

Kade Anderson was the third overall pick in last year’s draft after a successful stint at LSU, which included striking out 37.4% of the batters he faced in 2025.

This meant that 2026 was his first experience in professional baseball, and the Mariners decided to go with the aggressive approach to start him in Double-A, skipping High-A entirely. That may not have even been enough, as his immediate dominance at the level could earn him a promotion to Triple-A any day now. 

Heading into Friday, he had a minuscule 0.64 ERA and 0.86 WHIP, with a ridiculous 41.5% strikeout rate and 7.5% walk rate through three starts. That includes an 11-strikeout gem over five shutout innings in his second start, and he was on his way to another masterful outing on Friday in his fourth start of the year.

He had allowed only one hit through 4 ⅔ scoreless innings with eight strikeouts against the Corpus Christi Hooks before the game was suspended for the rest of the night due to rain. 

Travelers & Hooks going into a rain delay in the 5th. Kade Anderson was awesome tonight. Hooks had no chance. 4.2IP, 1H, 0R, 0BB, 8K, hit batter, 59 pitches, 39 strikes, 9 whiffs. pic.twitter.com/bnCxOmbdcd

— Mariners Minors (@MiLBMariners) April 25, 2026

Double-A simply looks too easy for the 21-year-old right now, who already has a four-pitch arsenal that looks like it could hold its own at the major league level. While an imminent promotion is not likely, I fully expect Anderson to make his debut at some point this season.

It could just be a cup of coffee at the end of September, but if Seattle’s rotation suffers an injury, the youngster could be its most talented replacement option.

If he didn't have enough upside already, he'll also get the benefit of pitching in one of the most pitcher-friendly ballparks in the league for half of his starts. Like Schultz and Tolle, who came before him, he'd be a must-add in all leagues with ace upside once promoted.

Verdict: Monitor for Mid-to-Late Season Promotion

More Fantasy Baseball Prospects and Rookies