This story was excerpted from Martín Gallegos’ A’s Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

Fresh off clobbering his ninth home run of April, Brent Rooker emerged from the kitchen inside the A’s clubhouse at the Oakland Coliseum holding a double-double from the postgame spread catered by In-N-Out Burger.

The double-double was Rooker’s second of the afternoon, which has become his tradition when indulging in the legendary burger joint. In fact, if you’re looking to eat like the reigning American League Player of the Week, here’s his order: Two double-doubles animal style with chilis and mustard, along with a side of well-done fries.

“I’ll get one with the chilis and without the chilis,” Rooker said. “I do like the chilis. They’re really good. But for two burgers, it’s a little much. It’s a lot of flavor and a little spicy, so I go one with and one without.”

Making customizations off the secret menu is a sign of a true In-N-Out connoisseur. But Rooker was not always a believer of the hype surrounding the California-based burger chain.

“I was a doubter,” Rooker said. “I wouldn’t say I was a hater. I was a doubter just because I hadn’t had an experience that wowed me.”

Born and raised in Tennessee and later attending Mississippi State, Rooker had only heard the tales of In-N-Out from afar. Once he finally got a taste of it in college during a tournament in the Los Angeles area, the experience was rather underwhelming.

“I appreciated the quality," Rooker said. “The quality of the beef is clearly a step above most fast food places. It was always good. I just thought it was a little boring in terms of taste.”

Speaking negatively about In-N-Out is sacrilege in California. Rooker knew this. So when he found out he was claimed by the A’s this offseason and would have the burgers more readily available, the outfielder reached out to his followers on Twitter in search of the perfect order.

Scouring through several different replies, Rooker found ‘the one’ from former Major League pitcher Cody Ponce, who is currently playing in Japan for the Hokkaido Nippon Ham Fighters. Shortly after his arrival to Arizona for Spring Training, Rooker drove to the nearest In-N-Out and ordered what has since become his usual.

“I think the addition of the mustard was the big thing,” Rooker said. “I didn’t realize when you order it regular, there’s no mustard on it. I think that makes it a little bland, so the addition of the mustard was good. The animal style on the burger, as well, upgrades it. … Since I’ve made those changes, I’m a big fan.”

It’s clear Rooker has a passion for burgers, which begs the big question: What is his Top 5?

“I’d say In-N-Out is No. 2," Rooker said. “Five Guys is my No. 1. I like Shake Shack a lot, so I’ll put that at three. Steak ‘n Shake probably four. Then, probably McDonald’s at five. I do like McDonald’s. That’s kind of a guilty pleasure. I’m pretty comfortable with that list.”