The Chicago White Sox traded reliever Seranthony Dominguez, outfielder Nolan Jones, and catcher Boston Smith to the Seattle Mariners in exchange for right-hander Luis Castillo, according to Jeff Passan of ESPN. Dominguez signed a two-year, $20 million contract with the White Sox this offseason to be the team's closer. He struggled as the team's closer earlier in the season, converting just 12 of 17 save opportunities and eventually lost the job to Grant Taylor and Sean Newcomb in June. The 31-year-old owns a 3.99 ERA, 1.33 WHIP, and 47 strikeouts across 38 1/3 innings. With Andres Munoz locked in as Seattle's closer, Dominguez will be used mostly in leverage situations. Fantasy managers can move on from Dominguez outside leagues that reward saves and holds, as he is third in the pecking order for save chances behind Munoz and Jose A. Ferrer.

From RotoBaller

Seattle Mariners top pitching prospect Kade Anderson should be on the radar of all fantasy managers heading into Week 19. On Saturday, the Mariners traded veteran right-handed pitcher Luis Castillo to the Chicago White Sox per ESPN's Jeff Passan. This move opens a role in their starting rotation for a potential sixth man. While Emerson Hancock currently occupies the No. 5 spot in the rotation, he has also been linked to many trade rumors, which would create an even clearer path for the team's No. 1 prospect to play a major role over the final stretch. Anderson has been knocking on the MLB door since making his pro debut in 2026. Through his first 16 starts at Double-A (82 1/3 innings), the southpaw has posted a dominant 1.20 ERA, 0.66 WHIP, and a 119:12 K:BB. Even if the Mariners were to hold Hancock through the deadline, Anderson could find a role as a sixth man in the staff. If Hancock were to move to a new club, the budding southpaw could earn the call immediately after. He is a priority stash target across all formats as he would hold must-start upside on a per-start basis.

From RotoBaller

The Los Angeles Dodgers traded outfielder prospect Zyhir Hope as the headliner in the deal that brought them left-handed pitcher Tarik Skubal on Saturday evening, according to Jeff Passan of ESPN. Hope was viewed as the No. 3-ranked prospect in the Dodgers system before the trade and sits as the No. 19 overall prospect in the sport on MLB Pipeline. Alongside Hope, the Dodgers traded right-handed pitchers River Ryan and Brady Smith. Hope has spent the entire 2026 season at the Double-A level and looked comfortable. Through 94 games at Tulsa, the budding star has posted a dominant .293/.363/.530 line with a .899 OPS, 17 doubles, 23 home runs, and 18 stolen bases. Fantasy managers should keep a close eye on his status as a late-season promotion to Triple-A Toledo is likely in play given how comfortable he has looked at Double-A. He is expected to compete for a 2027 MLB debut.

From RotoBaller

The Los Angeles Dodgers are trading right-handed pitching prospect River Ryan, alongside fellow right-hander Brady Smith and outfielder Zyhir Hope, to the Detroit Tigers in exchange for starting pitcher Tarik Skubal, per Jeff Passan of ESPN. While Hope is the headliner of this deal, Ryan holds high upside on his own. Ryan made his MLB debut in 2024 but logged only 20 1/3 innings with a sharp 1.33 ERA. However, the right-hander then underwent Tommy John surgery, which kept him off the field for all of 2025. Through 2026, Ryan has also been limited due to injuries but has been effective when on the Triple-A bump. With Detroit likely selling off other veteran pieces, Ryan should be in a great position to contend for his second MLB stint once he returns from his current hamstring injury. He is worth closely monitoring as he could emerge as a top stash candidate in the coming weeks.

From RotoBaller

Seattle Mariners right-hander Luis Castillo was traded to the Chicago White Sox in exchange for Seranthony Dominguez, Nolan Jones, and Boston Smith, according to Jeff Passan on ESPN. Castillo will head to Chicago to bolster the team's starting rotation as the White Sox make a playoff push. The 31-year-old struggled in his previous start against the Dodgers, allowing five runs on 11 hits across five innings. He didn't record a win in July and owned an ugly 5.48 ERA. Hopefully, the move to Chicago will help Castillo turn things around this season. He owns a (3-9) record along with a 5.06 WHIP, 1.39 WHIP, and an 86:32 K:BB across 99 2/3 innings. Chicago hopes to get the version of Castillo who posted a 3.50 ERA and a 1.15 WHIP from 2023-2025. It's unclear when Castillo will make his debut with the White Sox, but the change of scenery should only help him rebound from what is the worst season of his career so far.

From RotoBaller

Cardinals' RP Kyle Leahy had an ERA of 2.00 and a WHIP of 0.94 in 18 innings over his last three games. Leahy is owned only in 43.8% of mixed leagues.

Miami's CF Griffin Conine had a slash line of .389/.450/.889 going 7-for-18 with 5 RBIs in six games this week. Conine is owned only in 2.2% of mixed leagues.

San Francisco Giants' C Daniel Susac scored 27.0 fantasy points going 5-for-11 with three home runs and seven RBIs in four games this week. Susac is owned only in 0.6% of mixed leagues.

Mets' CF A.J. Ewing had three stolen bases and a .316 average with 3 RBIs in five games this week. Ewing is owned only in 39.5% of mixed leagues.

Baltimore Orioles' 2B Jackson Holliday had a slash line of .500/.526/.556 going 9-for-18 with 3 RBIs in five games this week. Holliday is owned only in 17.7% of mixed leagues.

Boston's CF Ceddanne Rafaela scored a phenomenal 40.5 fantasy points going 11-for-26 with four home runs and 10 RBIs in six games this week. Rafaela is owned in 64.9% of mixed leagues.

Cubs' SP David Peterson had an ERA of 1.45 and a WHIP of 0.75 in 18.2 innings over his last three games. Peterson is owned only in 16.7% of mixed leagues.

Braves' SP Martin Perez had an ERA of 1.69 and a WHIP of 1.06 in 16 innings over his last three games. Perez is owned only in 26.4% of mixed leagues.

Miami's LF Kyle Stowers scored 27.5 fantasy points going 6-for-21 with three home runs and three RBIs in six games this week. Stowers is owned in 54.3% of mixed leagues.

San Francisco Giants' CF Heliot Ramos had three stolen bases and a .292 average with 3 RBIs in six games this week. Ramos is owned only in 18.6% of mixed leagues.

Pirates' 1B Endy Rodriguez had three stolen bases and a .250 average in four games this week. Rodriguez is owned only in 0.9% of mixed leagues.

Kansas City's CF Tyler Tolbert had three stolen bases and a .500 average in four games this week. Tolbert is owned only in 2.6% of mixed leagues.

Orioles' SP Shane Baz had an ERA of 1.62 and a WHIP of 1.26 in 16.2 innings over his last three games. Baz is owned in 69.0% of mixed leagues.

Yankees' CF Spencer Jones scored 27.5 fantasy points going 6-for-17 with three home runs and six RBIs in six games this week. Jones is owned only in 2.3% of mixed leagues.

Yankees' 2B Jose Caballero had four stolen bases and a .286 average in five games this week. Caballero is owned only in 47.9% of mixed leagues.