The writing seemed to be on the wall that the Athletics were getting ready to trade fireballer closer Mason Miller when, despite being faced with a save situation in the 9th inning of their 5-4 victory over the Seattle Mariners on Wednesday night, Mark Kotsay did not turn to Miller. Kotsay stopped shy of providing a reason why Miller was unavailable after the game. The reason was provided in blockbuster fashion on Thursday, the day of the MLB trade deadline, as Miller and starting pitcher J.P. Sears were dealt to the San Diego Padres.
As everyone figured would be the case, the Athletics got a haul for Miller, including one of the best prospects in all of baseball.
The A's are receiving shortstop Leodalis De Vries, the No. 3 overall prospect in baseball, along with three pitchers from San Diego for Mason Miller and J.P. Sears, sources tell ESPN.
— Jeff Passan (@JeffPassan) July 31, 2025
Mason Miller heads to Padres in deal that could define A’s rebuild
After refusing to make Miller available at the trade deadline last season and holding onto him throughout the offseason, the Athletics cashed in on his trade value this season in a significant way.
Shortstop Leodali De Vries is certainly the prize of the package for the Athletics. Signed as an international free agent last year, De Vries has immediately risen in the ranks of MLB Pipeline's Top 100 list. A switch-hitting shortstop with power, De Vries certainly has the trajectory of being the next cornerstone player for the Athletics.
At 18 years old, De Vries is still several years away from being ready for the Major League level, which certainly is intriguing, considering the Athletics are expected to eventually land in Las Vegas. By the time the Athletics begin playing in Las Vegas, it's certainly possible that De Vries will be ready to become the face of the franchise. In high Class-A this season, De Vries is carrying a 116 wRC+ with 8 home runs through 368 plate appearances.
On the other side of the coin, Miller becomes the latest electric talent to leave the Athletics' organization almost as quickly as he reached the Major League level. Miller now joins a stacked National League West and is immediately inserted in a postseason push with the Padres.