Sept roster expansion accelerates a wave of rookies and returnees across MLB fantasy rosters. Mets promote Jonah Tong and Nolan McLean to help a six-man rotation down the stretch; Boston tab Payton Tolle to stabilize a rookie-heavy brood. Cincinnati’s Sal Stewart and Kansas City’s Carter Jensen arrive with multi-position upside, while Miami’s Connor Norby and Arizona’s Jordan Lawlar return from injuries and search for steady at-bats. The Reds also lean on Sal Stewart for spark while Perdomo’s extension with Arizona locks in infield predictability.

Risers collide with risk as first-timers settle in: Tong’s debut win over Miami signals potential multi-start value; Tolle impressed enough to stay in the rotation through September; Norby and Lawlar offer speculative upside in shallower formats; Ke’Bryan Hayes’ move (via trade context) and Perdomo’s extension shape the infield depth for late-season fantasy planning.

September callups close the 2025 season with a last wave of rookies that fantasy managers should monitor in redraft leagues. Jac Caglianone and Sal Stewart headline the 25-man Top 25, with Carter Jensen and Bryce Eldridge offering multi-category upside. Andrew Painter’s chances for an impact are tempered by innings limits, while Stewart’s .309/.383/.524 pace across Double-A/Triple-A signals real upside for Cincinnati. Overall, the piece blends ceiling with playing-time risk, highlighting stash-worthy long-term assets and near-term bargains.

As fantasy baseball season enters its crucial second half, monitoring emerging prospects is essential for teams aiming for success. Troy Melton, a rising pitcher with the Detroit Tigers, recently made his MLB debut with a solid minor league track record, boasting a 2.99 ERA and impressive strikeout rates. Meanwhile, Kansas City Royals catcher Carter Jensen has turned the corner after a slow start, showcasing his power and speed with 13 home runs and 8 stolen bases. Lastly, Owen Caissie of the Chicago Cubs has been a standout at Triple-A, launching 20 home runs this season, although his path to the majors may hinge on potential trades within the Cubs' roster.

The 2025 MLB season is heating up as Week 18 approaches, and it’s time to look at the top fantasy baseball prospects to stash. Key players like Carter Jensen from the Kansas City Royals is showing great promise with a significant improvement in his batting average and power numbers. As a catcher, his ability to not only hit but also manage the game behind the plate makes him a strategic stash for your team. Spencer Jones of the New York Yankees is making headlines with explosive performances, including multiple home runs and impressive exit velocities, suggesting he could soon be a fixture in the Bronx. Similarly, Brandon Sproat of the New York Mets is on a roll, showcasing an uptick in velocity and strikeout capabilities, positioning him as a potential call-up. Andrew Painter from the Philadelphia Phillies is also in the mix, with a chance to impact a playoff push despite some inconsistency. These players could be the key to your success as we inch closer to the season's peak.