OAKLAND -- The extremely tall head of long, red hair was greeted by former Oakland Athletic turned NBC Sports California broadcaster, Dallas Braden, near the home dugout on Aug. 20, 2019.

A.J. Puk had received his highly-anticipated promotion to the big leagues that day and appeared to settle right in during warm-ups.

He would make his official debut the next day in relief against the Yankees.

The 6-foot-7 lefty pitcher had all the ingredients it took to be successful with a team that suffered recent pitching setbacks, including a Frankie Montas PED-related suspension and a Jesús Luzardo injury.

But Puk finally was on the big stage after spending three seasons in the minors.

"You could kind of sense it," Puk told NBC Sports California in late January. "The guys in the clubhouse were kind of joking going like 'You're about to get called up.'"

The A's No. 2 prospect said his teammates assumed he would be a September call-up as the month neared. He wasn't sure if he was expecting the news before that in August.

"It was just great, you know," Puk said. "You finally get that call, you just achieved something you've been working for almost your whole life, and I was able to call and talk to my parents."

Puk, in Las Vegas with the Triple-A Aviators when he got the news at 11 p.m., called his mom first but she didn't answer. Then he called his dad, who took his call. Then, he called mom again.

"My mom called me back later -- she was in Florida at the time. She just rolled over randomly and saw it," Puk said.

Due to the time change, of course, it was 2:00 a.m. for her.

For the 24-year-old, there was no feeling of being the new kid in school. He had been to big league spring training before, so the faces surrounding him as he sported green and gold were familiar.

"I kind of knew most of the guys," he said. "I have the whole wave of guys that I came up with to get called up too, so it was great having all of those guys with me."

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Puk will head into the 2020 season as a member of the promising A's starting rotation. He will join Mike Fiers, Sean Manaea, Montas and Luzardo in the rotation.

With Triple-A Vegas in 2019, Puk posted a 4.91 ERA (give him a break, it's the PCL) with 16 strikeouts in 11 innings.

Last season, he was eased back into pitching after coming off Tommy John surgery in April 2018. He finished with a 3.18 ERA with 13 strikeouts in 11.1 innings with the A's, all out of the bullpen.