San Diego shockingly acquired 100-mph flamethrower Mason Miller from the A’s on Thursday in a massive move ahead of the MLB trade deadline, The Post’s Jon Heyman confirmed. San Diego is also receiving former Yankee lefty JP Sears, while the A’s are receiving four players, including the No. 3 prospect in the sport in shortstop Leo De Vries.

The Athletics traded closer Mason Miller to the San Diego Padres ahead of the deadline, but they did not see the deal coming.

The San Diego Padres offloaded a huge package to land Mason Miller from the Athletics at the MLB trade deadline. It was the biggest deal of the deadline, and it stunned the baseball world, as A.J. Preller gave up top prospect Leo De Vries, ranked 3rd by MLB Pipeline at the time of the trade.