WASHINGTON -- The Nationals’ top prospect has joined them in the bigs.

Catcher Keibert Ruiz will make his Washington debut on Monday, when he'll bat sixth against the Phillies at Nationals Park. Ruiz is ranked as the Nats' No. 1 prospect and MLB’s No. 19 prospect overall, per MLB Pipeline.

“I was very happy,” Ruiz said pregame. “I’m grateful for this opportunity, just looking forward to have some fun and get to know everybody.”

Ruiz was one of the headliners in the Nationals' mega deal that sent Max Scherzer and Trea Turner to the Dodgers on July 30. He instantly rose to the top of their prospects charts.

“We’re all excited about it,” manager Dave Martinez said. “He’s part of our future here.”

Coincidentally, Ruiz will catch starting right-hander Josiah Gray, with whom he was traded from Los Angeles, in his first game in a Nats uniform. The 23-year-olds have worked together at the Dodgers’ alternate training site and in Triple-A.

“It's really exciting,” said Gray. “Obviously, there's a lot of good ballplayers here, but they invested a lot in me and Keibert so it's going to be really fun. I'm sure [Monday] will be just that first glimpse of future things to come.”

Ruiz made his Major League debut with the Dodgers last season, appearing in two games, and he played in six more games with L.A. this season. This month, the switch-hitter has been mashing for the Triple-A Rochester Red Wings. He connected for back-to-back two-homer contests this month, and he slashed .308/.365/.577 in 20 games. Ruiz also tallied 24 hits, six doubles, five home runs, 14 RBIs, seven walks and six strikeouts.

“We just want him to have good, consistent at-bats,” Martinez said. “And the biggest thing that we’ll talk about is, stay up the middle of the field and take his walks.”

Defensively, Ruiz is excited to work with bullpen coach Henry Blanco on honing his game behind the plate at the big league level. The early plan is for Blanco to help with Ruiz’s release and foot quickness.

“He's going to make sure that you're on the same page,” Gray said of Ruiz’s game planning. “He's going to be really thorough with the scouting report, he's going to make sure that you're getting your pitches where you need to get them. … He's a really great catcher.”

In a corresponding move, the Nationals optioned fellow catcher Tres Barrera to Triple-A. Barrera had been sharing the starting duties behind the plate with Riley Adams. Over 30 games this season with the Nats, Barrera has batted .264 with 24 hits, three doubles, two home runs, 10 RBIs and eight runs scored.