When Jonah Heim learned of his callup to the Major Leagues on Monday morning, A’s manager Bob Melvin said the young catcher’s eyes lit up with a huge smile on his face.

Heim did not think anybody else in the world could possibly be more excited than he was in that moment. Then came the call to his father, James, who practically woke up his neighbors back home in Amherst, N.Y., after hearing the news.

“It was pretty emotional,” Heim said. “He’s been there since Day One and I wouldn’t be here without him and my family. I can’t thank them enough. As soon as I let him know, I think he ran into my brother’s room yelling at him to let him know. That was pretty special.”

Heim, Oakland’s No. 11 prospect, per MLB Pipeline, was in the starting lineup for Tuesday’s 10-3 win over the Rangers at Globe Life Field. The 25-year-old rookie catcher’s Major League debut came after seven seasons in the Minor Leagues. So you could see why the emotions would be high for both Jonah and James after the long grind that began in 2013 as a fourth-round pick by the Orioles.

Heim walked in his first plate appearance and later got his first Major League hit, a single in the seventh, ultimately coming around to score his first run as part of a five-run inning for Oakland. While it was a moment he’ll never forget, he won’t ever fully remember the entire experience after he “blacked out” while swinging at the 1-0 sinker from Kyle Gibson that he lined to left field.

“I don’t really remember swinging. I just remember feeling the ball hit the bat and running,” Heim said. “Seeing the ball hit the ground was like everything I worked for coming to life. It was awesome.”

Before pro ball, Heim’s dreams of reaching the Majors formulated in his childhood as a diehard Yankees fan, growing up idolizing catchers like Jorge Posada and Russell Martin.

“I tried to hold back some tears. It’s been a long time coming,” Heim said. “I don’t think he stopped screaming. Hopefully, he’s in a better place today. We’ll see how he is.”

Heim’s first Major League start comes against Texas right-hander Kyle Gibson. Being a switch-hitter, Heim figures to get most of his starts against righties, forming a semi-platoon with right-handed-hitting catcher Sean Murphy.

Heim has spent most of his time this season at the A’s alternate training camp in San Jose as a member of the club's taxi squad. While there is no true substitute for game action to stay sharp, the catcher feels he’s been able to keep his approach at the plate in good form, thanks to good competition against top A’s pitching prospects such as James Kaprielian, Daulton Jefferies and Grant Holmes during simulated games.

“Just seeing live pitching, you can’t really put a price on that,” Heim said. “When you’re facing the good arms down there, it’s pretty realistic because they’ve got big league stuff. I feel ready to go.”

Pinder on paternity leave
Chad Pinder flew home to South Carolina on Tuesday morning to be with his wife, Taylor, who is due to give birth to the couple’s first child. Originally expecting a due date in September, Pinder is racing against the clock a bit in order to make it back home for the birth.

“It happened a little bit earlier. Our fingers are crossed for him. He’s excited,” Melvin said. “I know it’s a difficult plane flight back being that you have to get there in a hurry and you can’t control how fast you get there. We’re all pulling for him.”

With Pinder on paternity leave for at least the next few days, the A’s added outfielder Seth Brown to their active roster from the club’s taxi squad.