In Week 15 of the 2025 fantasy baseball season, four lesser-owned hitters are rising as potential waiver wire gems. Matt Wallner of the Minnesota Twins, rostered at just 7%, has notably improved his strikeout rate and is hitting for power, making him an exciting outfield option. Milwaukee's Isaac Collins, at 4% rostered, is producing with a solid average and speed on the bases, though his hard contact numbers raise questions about sustainability. Meanwhile, Kody Clemens, also from the Twins, boasts impressive hard contact metrics and positional versatility, potentially offering fantasy managers a multi-position contributor. Finally, Victor Caratini of the Houston Astros is enjoying a career season, showcasing a strong batting average and emerging as a reliable catcher in fantasy leagues. As the All-Star break passes, these players present intriguing options for roster enhancement.