The Philadelphia Phillies fired manager Rob Thomson on Tuesday (April 28) after the team stumbled to a 9-19 start, matching the New York Mets for the worst record in Major League Baseball. Don Mattingly, a veteran manager with 12 seasons of experience, will take over as interim manager for the remainder of the 2026 season.

The move ends Thomson's four-and-a-half-season tenure with Philadelphia, during which he led the team to four consecutive playoff appearances and a World Series berth in 2022. Despite a .568 winning percentage and back-to-back National League East titles, the Phillies decided a change was necessary after the club's worst 28-game start since 2002.

The decision came amid a brutal 11-of-12-game losing streak that left the team 10.5 games behind the Atlanta Braves. The Phillies' struggles have affected every aspect of their game. The team ranks 28th in runs scored and team ERA, with key players like Alec Bohm and Kyle Schwarber batting under .200. Starting pitchers Jesus Luzardo, Aaron Nola, and Andrew Painter all carry ERAs above 5.00.

Philadelphia entered the season with the largest payroll in franchise history at just over $315 million and faced massive expectations as the defending NL East champions and host of this year's All-Star Game.

Philadelphia also announced that third-base coach Dusty Wathan was promoted to bench coach.

Thomson, nicknamed "Topper," joined the Phillies in 2018 as bench coach under former manager Gabe Kapler. He replaced Joe Girardi in June 2022 and immediately led the team to the World Series, where they lost to the Houston Astros in six games. However, the team regressed in subsequent postseasons, losing in the NL Championship Series in 2023 and in the NL Division Series in both 2024 and 2025.

Mattingly's hiring creates a historic first in baseball: a father-son manager-general manager combination. His son, Preston Mattingly, serves as Philadelphia's general manager under president of baseball operations Dave Dombrowski. Don Mattingly joined the Phillies as bench coach in January after spending time with the Toronto Blue Jays. He previously managed the Los Angeles Dodgers to a .551 winning percentage over five seasons and the Miami Marlins to a .430 winning percentage over seven seasons.

Mattingly now faces the challenge of reversing Philadelphia's fortunes during a favorable stretch of the schedule, with nine of the next 13 games at home against the San Francisco Giants, Oakland Athletics, and Colorado Rockies. The team will also benefit from ace Zack Wheeler returning from injury, having led the Phillies to their only win in 11 games this past Saturday against Atlanta.

Thomson is the second manager fired this season, following the dismissal of Alex Cora by the Boston Red Sox.