As the MLB season nears the halfway mark, optimizing fantasy rosters remains crucial for success. This week, the focus is on players under 40% rostered in Yahoo! leagues, presenting an opportunity for savvy managers to snag hidden gems. Key recommendations include Otto Lopez, whose impressive .333 batting average and dual eligibility provide solid value, and Kyle Stowers, showcasing power potential with a 19% barrel rate and a stellar hard-hit percentage.

Jo Adell is also highlighted despite his previous struggles, showing marked improvements in contact rates and power metrics, making him a worthwhile risk. Caleb Durbin and Tyler Freeman offer non-power contributions with high batting averages and contact rates, while pitchers Michael Soroka and Emmet Sheehan are discussed for their promising upside despite recent ERAs. Overall, these waiver picks could provide significant boosts as teams head into the second half of the season.