Assigned uniform No. 13, Perez was welcomed by his teammates; huddled with starting pitcher Felipe Paulino; undertook radio, TV and press interviews; took his swings in batting practice. He was in the Royals' lineup batting seventh and he's here for the rest of the season.
"He'll play quite a bit," manager Ned Yost said without being specific.
And he had a very busy debut in what turned into a numbing, 8-7 loss to the Rays. He got his first hit, a single up the middle, drove in a run and scored one. Most impressive, though, was his defensive work.
In the bottom of the fourth, Perez gave a demonstration of his strong, quick arm by snapping off a throw that picked off Casey Kotchman at first base. In the eighth, Perez again worked his pick-off magic, firing down to third base to nab Sam Fuld, who had strayed off on a busted squeeze play.
Those were the first pickoffs by any Royals catcher all season.
"I don't think we've even had a guy attempt to pick a guy off base all year long," Yost said.
Third baseman Mike Moustakas and first baseman Eric Hosmer also got credit on those pickoffs and shortstop Alcides Escobar on a near-miss attempt at second.
"On the receiving end, too, we've got guys that have played with Sal -- that was head's up on Moose and head's up on Hoz's part, and head's up on Esky's part. It takes two to tango to these deals and all three of those kids were alert and on their toes," Yost said.
From a strikeout that ended the fifth inning through the seventh, Perez had a very unusual string of seven straight putouts. Two were strikeouts, but five were on pop-ups including four in foul ground.
"I thought I played hard, like I've been doing at Omaha and Double-A. I played a hundred percent, I thought I was doing my job," Perez said.
No argument with that.
The decision to bring up Perez now instead of September when rosters are expanded was triggered by catcher Brayan Pena taking paternity leave. Yost needed a catcher and he discussed the issue with general manager Dayton Moore.
"What's the difference between now and three weeks from now?" Yost said.
"This thing with Brayan Pena came up and Dayton and I talked about it and said, 'Instead of four weeks' experience, let's give him seven weeks' experience.' It gives us a chance to [almost] double his experience at the big league level and we think he's going to be able to catch every day up here, but we need to see where we are with him."
Yost, a former catcher, is generally reserved in his praise for players. Not so with Perez, tall for a catcher at 6-foot-3 and at about 230 pounds, lighter than he was in Spring Training.
"He sets up very nice behind the plate, he's very quick, he's very agile, his feet work as good as any catcher's feet I've ever seen," Yost said. "I've never seen a catcher whose feet work as quickly as his do."
The quick feet help Perez get off quick throws which, among baseball folks, are timed to split seconds from catcher's glove to infielder's glove at second base. So, Yost scoffed when he first heard reports that Perez could clock throws at 1.85 seconds glove-to-glove.
"I've never seen a 1.85," Yost said at the time. "I've seen 1.91s or 1.9s. The Major League average is 2-flat."
Then his eyes were popped open.
"On my watch, this kid's throwing 1.86s, 1.85s and I thought I didn't know how to work the watch until everybody else had the exact same times," Yost recalled.
"He's not going to do it constantly but he can do it. A lot of it depends on the pitch, the location of the pitch. The kid gets himself consistently in a good throwing position where he deliver a good, strong, accurate throw to the bases -- as well as anybody I've ever seen."
Yost has seen a lot of catchers. This prize prospect, in his five Minor League seasons, has gunned out 147 of 348 base-stealers or a very good 42 percent. This year, for Omaha and Northwest Arkansas, Perez was 47-for-102, 46 percent. No attempts were made by the Rays in his first big league game.
"And this kid catches, he blocks and he's got a feel for calling the game," Yost added. "It's natural to him."
Perez's defensive skills helped him climb the Minor League ladder in fast order.
"It was pretty quick," he said. "Last year I started in High-A, this year in Double-A, they sent me to Triple-A and just in 12 games, here comes the big leagues. Wow!"
Yost was not surprised by the 21-year-old's rapid climb.
"The kid can catch and throw. If you can catch and throw, you're going to go fast," Yost said. "But the thing we like about him, too, is he has potential with the bat, too."
His stay at Omaha concluded with a seven-game hitting streak in which he was 13-for-29 (.448).
Perez becomes the 12th rookie on the Royals' current 25-man roster which is, by far, the youngest in the Majors at an average of 25 years, 338 days. Next: San Diego at 27 years, 201 days.
"We're getting younger and younger each day, but we're getting more talented each day, too," Yost said.