Not the territorial type, Trout -- the New Jersey prodigy playing out West -- is happy to welcome Harper -- the Las Vegas kid performing on the East Coast -- on the mountaintop.
"It's good for baseball," Trout said of a potentially fascinating rivalry that, in reality, is the furthest thing from the two athletes' minds. "Bryce is doing some great things. The main thing is staying healthy -- for both of us."
Part of what makes them so charismatic is the way they attack the game. Trout has Mantle's body, but goes about it in the fashion of Mays, playing with a visible joy and unadulterated passion. Teammates embraced him from Day 1.
Harper is more intense and outwardly driven by nature. Like Mantle, he carries his emotions on his sleeves -- at times, again like Mantle, to his detriment. But Harper clearly burns to be great.
What is not so well known about Trout and Harper is that they once were teammates. For six weeks following the 2011 season, they shared the outfield as members of the Arizona Fall League's Scottsdale Scorpions.
Most of the buzz surrounded wunderkind Harper, the first overall pick by the Nationals in the 2010 Draft. Trout, taken by the Angels 25th overall in the first round in 2009, had played a cameo role for the Halos in the second half of the '11 season, giving glimpses of the wondrous deeds to come.
"We got to know each other in that month and a half," Trout said. "He's a good dude. I remember that he came to the field ready to work; he was always in the weight room."
It was a remarkably talented team, even if it finished 14-22, last in the AFL's East Division.
Brandon Crawford and Joe Panik -- the heart of the World Series champion Giants' infield -- got to know each other as Scorpions that fall, forging a bond.
The catcher was Derek Norris, Nationals property at the time, along with Harper. The third baseman was Norris' new Padres teammate, Will Middlebrooks, then with the Red Sox. Brewers shortstop Jean Segura, a young Angel flyer, showed off his athleticism with the Scorpions. Fellow ex-Angel Hank Conger, now with the Astros, backed Norris along with Dan Butler of the Red Sox.
Other familiar names on the roster included outfielders Gary Brown and Alex Hassan. Cody Overbeck, a Phillies farmhand who hit 125 Minor League homers, was at first base.
"We had a lot of fun," Norris said. "We scored a lot of runs, but lost some 13-11 games. Everybody in the Fall League had a good time. It's a chance to meet and see these prospects you've read about. Harper was the new thing. Trout was the guy kind of knocking on the door."
Harper led the offense, hitting .333 with six homers and 26 RBIs in 25 games. Panik hit .323, Segura .310. Running on fumes after a long season, dividing his time between Double-A Arkansas and the Angels, Trout hit .245 with one homer. The power would arrive in his astounding 2012 season.
The pitching staff was filled with arms coming off injuries and raw prospects, and it took a pounding. The team was managed by Archie Baylor, current first-base coach of the Red Sox.
"Honestly? Yeah, I knew those guys were going to be special," Middlebrooks said when asked about Trout and Harper. "You could see how rare their ability was. Trout is one of the more humble athletes of that caliber you're ever going to meet.
"It's pretty cool to see those guys, what they've turned into, and to have had a relationship with them. Crawford and Panik were humble guys, too. They came every day to prepare and go to work."
Crawford, a fourth-round pick by the Giants out of UCLA in 2008, was the veteran at age 24. Panik, San Francisco's first-round choice (No. 29 overall) out of St. John's four months earlier, was making the transition from shortstop to second base.
"He reminded me of Buster [Posey] in the way he would go about things, the way he hit the ball up the middle," Crawford said of Panik. "I could tell he had something special."
Nobody has played better shortstop this season than Crawford, a deserving All-Star. Panik, a major contributor to the club's run to the 2014 championship, is showing he's for real with a solid season.
"We have a great relationship," Panik said. "Brandon makes my job easier -- just a great guy to play with. The game tends to beat up on you. Then you look over at Brandon, and everything's fine."
As for how the loaded Scorpions lineup set up, Middlebrooks said: "I think it went Crawford, Panik, Trout, Harper, me, Norris ... we had some guys who could hit."
The fortunate fans who caught the Arizona Fall League action in 2011 were witnesses to an amazing collection of talent that would go on to light up the national pastime.
Certainly there's never been a better 14-22 team.