Flip on any highlight show and you're nearly sure to see them, with those peach-fuzz faces and boyish features beneath their big league caps. Mike Trout makes a diving catch on the warning track. Manny Machado whacks another double into the corner at Camden Yards. Bryce Harper belts a tape-measure home run or barrels into a catcher ... or an outfield fence ... or whatever stands in his way. The next generation of baseball stars has arrived -- straight from the senior prom, it seems -- and these guys are changing the complexion of the grand ol' game. Derek Jeter is 39 and injured, left off the All-Star team for the first time in eight years. Matt Harvey is 24 and merciless, with a polished array of breaking pitches to complement 98 mph heat. "These guys are coming up now with incredible talent, these young players," National League manager Bruce Bochy said Monday at Citi Field, where the New York Mets are hosting the All-Star game for the first time since Shea Stadium opened in 1964. "I think they are just getting better, faster, bigger, stronger still, and it's impressive to watch." No kidding. Trout and Harper, the Rookies of the Year last season, are making their second trip to the All-Star game. This time, they will start Tuesday night after getting elected by fans with a fervor for the new boys of summer. Some of baseball's best players are among the youngest on the field. Night after night, they put up unprecedented numbers and turn in spectacular plays that belie a birth certificate from the 1990s. "It's good for the game," Trout said. "A lot of young guys are playing fearless and making a name for themselves at an early stage in their career." Not only that, they move merchandise. Jersey sales for Harvey, Harper and Trout rank among the top 10 this season based on purchases of Majestic tops at MLB.com, the league and the players' association said last week. Harper is 20, and Trout is all of 21. Barely old enough to vote, let alone buy a drink. Machado's jersey ranked eighth, one spot behind Jeter, even though the Baltimore third baseman has spent less than a year in the majors. That didn't stop him from earning his first All-Star selection on his 21st birthday. "In today's era, young dudes are getting better and more prepared to come up to the big leagues," said Orioles teammate Adam Jones, an All-Star himself. "It's just an improvement in the game. These young dudes are phenoms, and he's put his name up there. "He's probably more mature than I am, and I'm 27." Machado was voted in by players, a significant sign of respect from his peers. Well, mostly elders, actually. He certainly deserved it at a power-packed position after hitting 39 doubles in the first half, threatening the single-season record of 67 set by Earl Webb in 1931. "Swing and hit the white ball coming at you. That's all it is," Machado said. "There's no secret to it." Just like Little League, apparently. Sometimes he makes it look that easy, too. But take a swing around the majors and you see it's not only Trout, Harper and Machado. There is Miami rookie Jose Fernandez, a 20-year-old All-Star with a Cy Young future. Don't forget lefty Patrick Corbin (23), who is 11-1 with a 2.35 ERA for Arizona. And second-year shortstop Jean Segura in Milwaukee, who leads the NL in hits at age 23. "I feel pretty good when they compare me with those guys," Segura said about his place among baseball's new breed. Then there's Harvey, the New York Mets ace with 29 major league starts to his name. His next one will be Tuesday night on his home mound opposite Detroit Tigers right-hander Max Scherzer. "For me, he's the best pitcher in the game," Diamondbacks outfielder Cody Ross said this month. "Not even just in the National League. He's really good. I faced a lot of those guys in the American League last year and I can't say that I saw anyone better than him. "His mound presence is as good as you'll see." There are 12 All-Stars this season 24 or younger, seven in the National League. That's the most since a dozen were selected in 1993, according to STATS -- a group that included Ken Griffey Jr., Mike Piazza, Gary Sheffield, Mike Mussina and Juan Gonzalez. The only player from that bunch under 23 was 21-year-old catcher Ivan Rodriguez. This year, there are four. That doesn't include Los Angeles Dodgers sensation Yasiel Puig, left out of the game after six electric weeks in the big leagues at 22. More to come from him, for sure. "Every guy that you just mentioned plays the game hard, plays it the right way every day. It's so much fun to be part of that," Harper said. "I'm not going to back off the throttle at all. I'm full speed every day." In all, 12 players who qualified as rookies last season made the All-Star team this year. So much for sophomore slumps. "There's definitely a different breed of ballplayer coming out," Minnesota manager Ron Gardenhire said last weekend. "This seems to be one of those cycles where a lot of young players are flashing quick." Although fresh faces are taking over, that doesn't mean all the old guys are out. Mariano Rivera, Torii Hunter, Carlos Beltran and Bartolo Colon are back at the Midsummer Classic, bringing decades of experience and wisdom. And what impresses veterans the most about this crop of young stars is the way they carry themselves on and off the field. Harper occasionally flashes a hot temper with Washington, but opponents predominantly praise them for their all-around skill and steady performance. "It's different from when I first came up. Just the attention, the media coverage, the pressure," said Twins catcher Joe Mauer, a No. 1 draft pick who made his first All-Star appearance at 23. "To keep everything in perspective and go out there and do your job every day and stay consistent is really what makes it pretty special. "A lot of guys can come up and have immediate success right away and the league can kind of figure you out a little bit. But those guys keep going day after day and keep producing." Yankees manager Joe Girardi is reminded of the mid-90s when Jeter, Alex Rodriguez and Nomar Garciaparra all broke in at shortstop in the American League. "It is kind of amazing the level that these young guys are playing," Girardi said. Making them just the sort of stars baseball wants to build around. "I like the fact that they play the game the right way. They seem to get it," Minnesota general manager Terry Ryan said. "They're gifted, they're energetic. It's good to see a young, up-and-coming player that represents not only their franchise well but the game well."