In the competitive landscape of Major League Baseball (MLB), the performance of players who exceed preseason expectations plays a pivotal role in determining a team's success. Each team in the MLB has had its fair share of surprises in 2025, where emerging talents and veterans alike have outperformed their projections. This article examines the standout players who have become the best-kept secrets for their respective teams, providing insights for fans looking to understand the contributions that may not have been on their radar.

For the New York Yankees, Fernando Cruz has shown significant promise, achieving a 2.66 ERA in 21 appearances before facing a setback due to right shoulder inflammation. Acquired through a trade involving Jose Trevino, Cruz has struck out an impressive 13.3 batters per nine innings in his debut season. Meanwhile, the Tampa Bay Rays' José Caballero, who stole a league-leading 44 bases the previous year, has improved his success rate this season, successfully stealing 19 out of 23 attempts while raising his OPS from .630 to .735. The Toronto Blue Jays' Addison Barger, a sixth-round pick in the 2018 draft, has quickly established himself as a key player, boasting 11 doubles and an .801 OPS in his first 37 games, coupled with defensive versatility across several positions.

Brennan Bernardino of the Boston Red Sox has notably bounced back from a challenging 2024 season, showcasing a 1.27 ERA in 27 appearances this year. Similarly, Bryan Baker has emerged as a reliable bullpen option for the Baltimore Orioles with a 2.88 ERA in his first 26 games. The Detroit Tigers' Will Vest has also exceeded expectations, recording a 2.00 ERA in 25 appearances, further solidifying the team's bullpen. In the American League Central, Daniel Schneemann has stepped up for the Cleveland Guardians with seven home runs and a .779 OPS, effectively bridging the gap until Travis Bazzana’s return. Minnesota Twins pitcher Louis Varland has demonstrated an impressive performance with a 2.73 ERA, providing added depth to the team’s pitching staff.

The Kansas City Royals have benefited from Noah Cameron's promotion, as he has posted a remarkable 1.05 ERA in his first four starts of the season. Mike Vasil has emerged as a noteworthy option for the Chicago White Sox, maintaining a strong 2.10 ERA despite concerns regarding his FIP. Gabe Speier has turned heads with the Seattle Mariners, significantly lowering his walk rate while posting a 2.01 ERA. In Houston, Bennett Sousa has emerged in the Astros bullpen with a respectable 2.50 ERA through 15 appearances. Robert Garcia has also proved to be a sound acquisition for the Texas Rangers, boasting a 2.25 ERA and deepening the team's relief pitching.

José Soriano has transitioned into a quality starter for the Los Angeles Angels, evolving from a bullpen role to post a 3.42 ERA. Meanwhile, Jacob Wilson has been making waves with the Oakland Athletics, hitting .345 while showing promise as a candidate for AL Rookie of the Year. The Philadelphia Phillies’ Tanner Banks is taking on a greater role in their bullpen, reflecting his growth into a more significant contributor. Reed Garrett has transformed into a reliable option for the New York Mets, achieving a standout 0.73 ERA in 25 games. The Washington Nationals' Cole Henry has also provided stability with a 2.14 ERA.

In the National League, Daysbel Hernández of the Atlanta Braves has showcased his potential and high strikeout ability despite some control issues. Valente Bellozo of the Miami Marlins has made a positive impact with a 2.89 ERA over 28 innings. Similarly, Caleb Thielbar, an experienced actor on the Chicago Cubs, has shown his effectiveness with a 2.29 ERA while Kyle Leahy has stood out as a setup man for the St. Louis Cardinals with a 2.08 ERA. Abner Uribe continues to establish himself for the Milwaukee Brewers with an impressive 1.65 ERA, showcasing the depth of the team’s bullpen. In Cincinnati, Lyon Richardson has made a strong statement with a low earned run tally over limited appearances.

Dennis Santana has become a valuable asset for the Pittsburgh Pirates with a stellar 1.48 ERA in 25 games following his acquisition. The Los Angeles Dodgers' Jack Dreyer has stepped up in the absence of key bullpen members, contributing a 2.97 ERA in his first season. Gavin Sheets has revitalized his career with the San Diego Padres, increasing both his batting average and OPS significantly. Finally, Randy Rodríguez has returned as one of the leading relievers for the San Francisco Giants, vastly improving his ERA from the previous season. Shelby Miller's resurgence with the Arizona Diamondbacks, featuring a 1.99 ERA, adds another layer to the conversation regarding player development and adaptability. While the Colorado Rockies face challenges, Jordan Beck's offensive production has provided a glimmer of hope amid a difficult season.