Brewers lose top executive to Athletics right after World Series win

The Milwaukee Brewers have not even finished popping champagne from their first World Series championship in franchise history.

And already, one of the key architects of that title is leaving.

According to Ken Rosenthal of The Athletic, the Athletics are hiring Cam Castro away from the World Series champion Brewers as their general manager.

Castro will work under newly appointed president of baseball operations Taylor Smith.

The move makes Castro the second-highest executive in the Athletics’ front office.

Castro, 36, spent seven years in the Brewers organization.

He joined Milwaukee in 2019 after coaching at Lake Erie College and serving as a pitching coach in the Brewers’ minor league system.

His rise through the ranks was steady.

He first became director of pitching development.

Then he took over as vice president of player development.

Most recently, he served as senior vice president of player development and performance.

In that role, Castro oversaw the entire pipeline that produced the young talent fueling Milwaukee’s championship run.

The Brewers finished the 2026 regular season with 103 wins — the best record in Major League Baseball.

They did it with a payroll ranked 19th out of 30 teams.

Castro’s player development system was a major reason the small-market club could compete with big-spending franchises.

Now the Athletics are betting he can do the same thing in Sacramento.

The A’s are in the middle of their own rebuild.

They have made progress developing position players like Nick Kurtz, Tyler Soderstrom and Zak Gelof.

But their pitching pipeline has not kept pace.

That is where Castro comes in.

His background is in pitching development.

He started his coaching career as a pitching coach in the Brewers’ minor league system.

He will have several young arms to work with in Oakland.

Gage Jump, 23, made his major league debut this year.

Luis Morales, Kade Morris and Braden Nett are all younger than 25.

Castro’s job will be to turn those prospects into big-league contributors.

The Athletics hired Taylor Smith as president of baseball operations earlier this offseason.

Smith is now building his front office.

Castro is his first major hire.

For the Brewers, the loss stings.

Not because it was unexpected — front-office talent gets poached after championships.

But because Castro was not just any executive.

He was the guy who built the system that made Milwaukee’s title possible.

The Brewers won the World Series on Oct. 28, 2026.

They defeated the Los Angeles Dodgers in six games.

It was the first championship in franchise history, which began in 1969 as the Seattle Pilots.

The team moved to Milwaukee in 1970.

They had not won a pennant since 1982.

Now they are champions.

And the front office that built that team is already being picked apart.

Castro is the first known departure.

He may not be the last.

Rosenthal reported that other teams are expected to pursue Brewers players, coaches and front-office personnel this offseason.

That is the cost of winning.

Small-market teams like Milwaukee cannot match the salaries and titles that larger organizations can offer.

When their executives succeed, they get poached.

Castro’s move is a promotion.

He goes from senior vice president to general manager.

He goes from working under a president of baseball operations to being the second-in-command of an entire franchise.

For the Athletics, the hire signals a shift in strategy.

The A’s have long been known for their analytics-driven, low-payroll approach.

But they have struggled to develop pitching.

Castro’s track record suggests he can fix that.

In Milwaukee, he helped build a pitching pipeline that produced Corbin Burnes, Brandon Woodruff and Freddy Peralta in earlier years.

More recently, the system churned out young arms that kept the Brewers competitive even after those aces left.

The Brewers won the World Series with a pitching staff that relied on homegrown talent.

Castro had a hand in developing most of it.

Now he will try to replicate that success in Sacramento.

The Athletics are scheduled to move to Las Vegas in the coming years.

But for now, they play in Sacramento’s Sutter Health Park.

Building a winner in a temporary home is not easy.

Castro will have to recruit free agents and develop prospects without the stability of a permanent ballpark.

That is part of the challenge that attracted him.

People close to the organization say Castro is excited about the opportunity to build something from the ground up.

The Brewers, meanwhile, will have to find a replacement.

They have internal candidates who could step up.

But replacing a senior vice president of player development who just helped win a title is not simple.

The timing makes it harder.

The offseason is when front offices do their most important work.

Free agency begins soon.