As the 2025 MLB season heats up, Week 4's fantasy baseball waiver wire offers several intriguing outfielders worth considering for your roster. Tyler Fitzgerald of the San Francisco Giants has been on fire, showcasing a .444 batting average with two home runs and six RBIs in his last seven games. His dual eligibility at OF, 2B, or SS makes him a valuable pick-up for those looking to capitalize on his hot streak.

Similarly, Sal Frelick from the Milwaukee Brewers is excelling with a .319 batting average and five steals, making him a solid volume play. Meanwhile, Houston Astros rookie Cam Smith is building on his momentum, having recently notched his first multi-homer game. For deeper leagues, Austin Hays and Heston Kjerstad are generating buzz with power potential, while Mike Yastrzemski offers a temporary boost due to favorable matchups.

April 18 presents a 11-game MLB DFS slate on DraftKings and FanDuel. Players are advised to monitor injury news and starting lineups diligently as they build their fantasy rosters.

Pitcher Yoshinobu Yamamoto stands out against Texas, boasting a high strikeout rate and excellent run prevention metrics. Alternatives include MacKenzie Gore at Coors Field, who has shown solid metrics and faces a struggling Rockies lineup.

Among infielders, Ozzie Albies is a strong pick against Chris Paddack, while Junior Caminero is heating up with power against Carlos Rodon. Ryan Mountcastle is another value option against Andrew Abbott.

In the outfield, Randy Arozarena shows promise against Bowden Francis, while Austin Hays and Sal Frelick are expected to perform well given their favorable matchups. Stacking the Baltimore Orioles against Andrew Abbott is recommended due to the high projected run total.

Austin Hays made a remarkable debut with the Cincinnati Reds against the Seattle Mariners, showcasing his prowess at the plate. He finished the game batting 3-for-4, with a standout performance that included four RBIs. His pivotal moment came in the fifth inning, where he blasted a go-ahead three-run homer to center field, propelling the Reds from a 2-0 deficit to a 6-4 lead. This impressive outing followed a strong spring training, although Hays had started the season on the injured list due to a minor calf strain. His return to the lineup appears to have fully restored his power, as he demonstrated no signs of lingering effects from the injury.

The Cincinnati Reds activated key players Alexis Diaz, Matt McLain, and Austin Hays ahead of their series against the Seattle Mariners, marking a significant boost for the team. Diaz, who was expected to be the closer, had been sidelined with a hamstring strain but returns just as Emilio Pagán has shone with a 1.23 ERA. McLain returns to second base after recovering from a hamstring issue and is positioned at the top of the lineup, while Hays, newly signed from Baltimore, makes his debut as the designated hitter after overcoming a calf strain.

With five wins in their last six games, including a recent sweep against Pittsburgh, the Reds aim to capitalize on this momentum with a fully operational roster. This newfound health could be pivotal as they face the Mariners in the next three games, all eyes on how these returning players can impact the lineup and overall team performance.