As the 2025 MLB season enters Week 5, several players are making headlines with impressive performances. Jose Quintana of the Milwaukee Brewers has shown early promise with a 1.14 ERA, but given his expected batting average against, he may not be a reliable long-term option and is recommended as a sell. In contrast, Austin Hays from the Cincinnati Reds is on fire, boasting a .388 batting average with five homers, making him a strong buy. Jorge Polanco of the Seattle Mariners is also contributing significantly, hitting .377 with seven home runs, suggesting he's worth picking up. The Miami Marlins' Agustin Ramirez has made a splash in his debut, while Noelvi Marte from the Reds is reclaiming his prospect status with a strong showing. With these insights, fantasy managers must stay proactive on the waiver wire.