As the 2025 MLB season approaches its midpoint, fantasy managers are buzzing about the latest crop of prospects making their major league debuts. With injuries and performance struggles afflicting many teams, organizations are turning to their minor league systems for fresh talent to bolster their rosters.

Jac Caglianone, first baseman for the Kansas City Royals, is making headlines after a dominant minor league campaign, hitting .322 with 15 homers. He’s expected to get significant playing time as a right fielder. Cole Young, now with the Seattle Mariners, is also a name to watch after a solid stint in Triple-A, offering potential at second base. Meanwhile, the Boston Red Sox have called up Marcelo Mayer, whose impressive minor league stats suggest significant upside despite a slow start at the big league level.

Marcelo Mayer, the Boston Red Sox's highly touted prospect, has made his MLB debut, showcasing promising talent in his first few games. The 22-year-old, ranked No. 8 on MLB's top prospects list, demonstrated his capability with notable hits and an impressive OPS. However, his groundball tendencies and struggles with non-fastball pitches may challenge his consistency against major league pitchers.

Denzel Clarke debuted with the Oakland Athletics but faced early struggles, managing only one hit in 19 at-bats. Known for his size and speed, Clarke's high strikeout rate poses concerns, highlighting the need for adjustment at the major league level. Meanwhile, Robert Hassell III of the Washington Nationals has shown flashes of potential since his promotion, including a three-hit game and his first home run. With a solid batting average in Triple-A prior to his call-up, he could be a key player as the Nationals rebuild post-Juan Soto trade.

Robert Hassell III of the Washington Nationals emerges as a key fantasy baseball pickup for Week 9 of 2025. Promoted recently, he's currently ranked as the No. 11 prospect in the Nationals' system. In his brief stint at Triple-A, he showcased impressive stats with a .288 batting average and nine stolen bases. Though he had a rocky start in the majors with a hitless streak, his initial debut was promising with a 2-for-5 performance including a stolen base. With injuries affecting teammates Jacob Young and Dylan Crews, Hassell is expected to secure a regular starting role.

As the fantasy baseball season progresses, some hidden gems emerge on the waiver wire, promising to outperform their more popular peers. The Chicago Cubs' Matt Shaw, available in 74% of ESPN leagues, has transformed following a Triple-A stint. After struggling initially, he returned with a .360 batting average and improved strikeout rate. Similarly, the Los Angeles Angels' Zach Neto has shown resilience after shoulder surgery, boasting a .284 average with impressive power numbers.

Pittsburgh Pirates' Spencer Horwitz, available in 90% of leagues, is generating buzz due to his plate discipline and potential for growth, even though he may be limited against left-handers. For deeper leagues, the Washington Nationals’ Robert Hassell III represents a post-hype prospect, now getting consistent playing time and the chance to leverage the team’s aggressive base running. The Cubs' Daniel Palencia is a closer in the making, while Jameson Taillon offers two-start potential against weak opponents. Hayden Birdsong, adjusting from relief to rotation, is a deeper league target for his high strikeout rates.

The Week 9 waiver wire analysis for fantasy baseball focuses on intriguing, yet risky players including outfielders Will Benson and Robert Hassell III, as well as pitcher Mike Burrows. Benson's volatile hitting profile raises concerns despite his recent power surge; he's known for high strikeout rates. Hassell, filling in for the injured Dylan Crews, offers speed but lacks power potential. Burrows has shown promise with solid strikeout numbers but faces tough matchups ahead, limiting his immediate appeal. Each player presents unique risks and potential rewards for your fantasy roster.