PEORIA, Ariz. -- Through the generations, young baseball players from all over the world have always come up the pipeline. And they are perhaps getting better.

The MLB College Showcase is making a post-pandemic return for the first time in three years, bringing 28 players under age 20 and representing 11 countries. The event kicked off in the Phoenix suburb of Peoria, Ariz., where the MLB World Select Team gathered on a hot first day of October pushing 100 degrees to work out and play an afternoon scrimmage.

“When I was 18 years old, I never got an opportunity like this to come showcase and see the best players in the world at my age,” the team’s pitching coach Roger McDowell said on Saturday, while warming up starter Adam Bates, a 17-year-old, 6-foot-1 right-hander from Australia. “It’s kind of eye-opening, because I know I wasn’t this good at 18.”

McDowell wasn’t that much older than this roster of players when he broke into professional baseball in 1982 at the age of 21 with the Shelby (N.C.) Mets in A ball. That led to 12 years and 159 saves as a big league pitcher, including as the Game 7 winner with the New York Mets in the 1986 World Series.

McDowell got his first look at his young pitchers three days earlier.

“There’s not a whole lot of delivery or mechanical adjustments per se until you really see them compete, when you get in competition and face hitters,” he said. “And the other thing is it’s kind of unfair to the kid, too, to start making adjustments. You don’t know if those adjustments are something that’s going to benefit them.”

He did find a way to retool the leg work of 16-year-old Giacomo Taschin, a lefty from Italy, who said he appreciated the tutelage.

“Very good. The mechanics, the adjustments are very good,” Taschin said, with more than enough English to get by.

All roster players are between 16 and 18, plus one player who turned 19 in August. They hail from Australia, China, The Netherlands, Czech Republic, Italy, Argentina, Germany, Curacao, Spain, France and Brazil. On this same day, across the world in Panama City, Brazil beat Nicaragua, 4-1, in a World Baseball Classic qualifier to advance to Tuesday’s play-in game. The 2023 World Baseball Classic starts in March.

The teenage players in the Valley of the Sun this month are exposed to high-level competition in the U.S. while also introducing them to U.S. college scouts, many of whom were on hand.

Some of the players from Europe might also be considered for a spot in the Elite European Development Tournament that will take place in connection with the 2023 London Series, when the St. Louis Cardinals and Chicago Cubs meet next summer in the U.K.

“I can’t imagine being in their situation. Leaving their country, and some of them probably have never been out of their country, and they come here for a whole month,” coach Jon Debus, who works with the catchers, said. “They’re still kids.”

The former bullpen coach with the New York Mets (2011) and Los Angeles Dodgers (2005) has spent more than 40 years in professional baseball as a player and coach.

“They’re sponges for knowledge, they listen, they’re very attentive to the schedule,” he said. “They’re just learning what it’s like to be a professional.”

Language barriers haven’t been an issue, said coach Jeff Conine. Conine spent 17 years in the big leagues through 2007 where he was a two-time All-Star with the Marlins (1994, ’95) and piled up almost 8,000 plate appearances.

Translators have been helpful when needed. But for the most part, Conine says, the coaches know how to convey important skills and the players know how to process it.

“Baseball is a language, and they all understand by visual cues,” he said while watching players take reps in the batting cage. “When I talk about hitting, they know what I’m talking about even though I’m not speaking to them [in their language].”

Conine has heard the players say that these Spring Training sites throughout Phoenix are the best fields on which they’ve ever played compared to their home countries -- even the auxiliary practice fields behind the Peoria Sports Complex’ main stadium, which hosts the San Diego Padres and Seattle Mariners during spring.

The first day of U.S. workouts saw the players walk onto the manicured playing surfaces at Salt River Fields at Talking Stick, the Scottsdale spring home of the Arizona Diamondbacks.

Their actual skills, though, are individually consistent, Conine added.

“These guys are quite advanced. I didn’t know what to expect when I got here because I’ve never worked with this program before,” he said. “I didn’t know what to expect from the international programs and what their coaching was like. I’m pleasantly surprised at their skill level.”

The roster includes seven Australians, five from the Czech Republic, four from The Netherlands, three from China, two from Brazil, two from Italy and one player each from Argentina, France, Germany, Curacao and Spain.

“They’re here for a reason, they’re here for a purpose,” Conine said.