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

SEATTLE -- With his Nationals bag in hand, fans in Seattle spotted Amos Willingham on Monday and asked him to sign a baseball.

The right-hander penned only his name, prompting a question.

“What number will you be wearing?” the fans asked.

Willingham paused. After being told Sunday night in Rochester, N.Y., that he was being called up to the Major Leagues and he needed to fly to Seattle the next morning to join the Nationals, his uniform number was a detail he didn’t yet have.

“I was like, ‘I don't know,’” Willingham replied. “‘I’ll find out.’”

Willingham entered the visiting clubhouse at T-Mobile Park hours later to see a No. 54 jersey with his name on it. (The number became available this season after Cade Cavalli switched to No. 24.) Willingham also saw several familiar faces from Triple-A as well as new teammates welcoming him to the big leagues.

“I don’t know if my heart’s gone below 100 beats per minute the whole time,” Willingham said shortly after settling into his locker among the Nationals relievers.

Willingham, 24, has been in the Nats organization since he was selected in the 17th round of the 2019 Draft out of Georgia Tech. He anticipated he would have a good season this year, but he didn’t know he would arrive in the Majors this soon. Willingham jumped from Double-A to Triple-A on May 14 and then to the bigs six weeks later.

The Nationals saw improvement in his command, strike-throwing and secondary pitch usage. In 20 Minor League appearances this season, Willingham -- who describes himself as “very fastball-heavy” -- went 4-1 with a 1.90 ERA, .198 opponents’ batting average and five saves across 23 2/3 innings.

“Kudos to him for working hard and getting up here,” said manager Dave Martinez. “Now the big thing is to stay up here … I’m excited. Here’s a guy that we drafted late, developed him and he’s here to try to help us win games.”

Willingham had never been to Seattle before; the Georgia native’s travels had taken him as far as Arizona. His first trip to the West Coast also could be his first trip to a Major League mound.

“[I am anticipating] the rush of when they open the gate and it's just a field and the crowd in the stands out there,” Willingham said. “I'm sure it's just going to be a huge adrenaline rush, probably some nerves, but also a lot of excitement.”