John McDonnell/TWP

Sunday morning, about 10 minutes until 10, Anthony Rendon ambled down the corridor inside Citi Field, two black gloves in his left hand and a blue duffel bag slung over his shoulder. He opened the door to the Nationals‘ clubhouse, found the locker marked with a ‘6’ above it and set down his bag.

“Ant, go to the skipper’s office and say hey,” Chad Tracy, the only other player present, said from across the room. “First door on the right.”

Rendon slipped off his black jacket and walked to see Davey Johnson. It had settled in on the cab drive over, as he stared out the window and looked up at the tall buildings. “Dang,” he thought. “I guess it’s really happening.” Rendon, at 22, had become a major leaguer.

“It was probably just like everybody else,” Rendon said. “I was like, ‘Are you serious?’ You’re not going to believe it at the time. But obviously when it finally sets in you know they’re serious and you’re getting called up.”

In the clubhouse, Rendon entered the manager’s office. “How was your trip in?” Johnson asked. “Long,” Rendon replied.

Bench coach Randy Knorr walked past and looked into the room. “Welcome, kid!” he said. “All right!”

“I’m gonna put you in the lineup,” Johnson said. Sure enough, when Knorr posted the lineup card an hour later Rendon was hitting sixth, playing third base in place of Ryan Zimmerman, who had been placed on the disabled list with a strained left hamstring.

Rendon laughed and walked back to his locker. He removed his black cowboy boots and unpacked his bag, welcome interruptions coming. “Nice hair,” pitching coach Steve McCatty said before leaning into embrace him. “Congratulations, brother.”

A day earlier, Rendon had been in the lineup at Class AA Harrisburg, where for 14 games he batted .292/.462/.500. He was taking a shower before a doubleheader when Harrisburg Manager Matt LeCroy poked his head between the curtain. “Hey,” LeCroy said, “see me in my office.”

Rendon wondered if he had done something to get himself in trouble. After he finished with his shower, Rendon walked into LeCroy’s office and learned he would be joining the Nationals in New York. He called his parents, Rene and Bridget, a working-class couple from Houston.

“It was pretty emotional, obviously, especially my mom,” Rendon said. “They’re excited. Right when I told my mom she was like, ‘Oh my gosh, I’m about to cry.’ And then she got teary-eyed and I teared up a little bit. It was good. It was a good moment.”

Bridget and Rene bought plane tickets to see their son in New York. When they arrived at the airport this morning, they were saddened to learn a miscommunication within the airline had lost their seats, despite the confirmation numbers in hand. “Bad story,” Rendon said. Instead, his parents will come see him play Monday, his first game in Washington.

They can at least count on him playing. Johnson plans to start Rendon at third base until Zimmerman’s return, which is expected to come in the first week of May. On a team with World Series aspirations, Rendon, the sixth overall pick in 2011, will be a temporary key component. Is he ready?

“There’s only one way to find out,” Rendon said. “That’s to be here. I’m pretty confident. I’m a confident person, at least I try to be, I try to do the best that I can in everything I do, and we’ll just see how it plays out.”