More than nine years later, the impression remains vivid.
"That day I threw to Pedro, I thought he had a chance to be in the big leagues," Pena recalled. "And he made it. He's there."
Pena and Alvarez remained in touch after that meeting -- through Alvarez's standout career at Vanderbilt University and his selection as the No. 2 overall pick in the 2008 First-Year Player Draft and his arrival in Pittsburgh.
The two were reunited on the baseball field Monday, with Pena throwing to Alvarez, a first-time Chevrolet Home Run Derby participant, in front of a sellout crowd and a national audience. And 15 miles away from the high school field on which Alvarez used to shine, the Pirates third baseman turned heads again.
Alvarez tallied six home runs -- the longest a 461-foot blast to the right-field upper deck -- at New York's Citi Field before recording 10 first-round outs. The total was not enough to advance to the Derby semifinals, though it did equal the number of home runs hit by the Pirates' four previous Derby hitters: Jason Bay, Barry Bonds, Bobby Bonilla and Andrew McCutchen.
"I don't think it's hit me yet, to be honest with you," Alvarez said shortly after Oakland's Yoenis Cespedes took the Derby crown. "It was a surreal experience. Obviously, I've never experienced something like that. I was glad to be a part of something like that. It was a blast."
A product of the Horace Mann School in New York City, Alvarez said it was an "easy decision" to select Pena, now the third-base coach with the Pirates' Class A Bradenton (Fla.) affiliate, to pitch to him.
Pena didn't hesitate in accepting the invitation.
"It's an honor for me," Pena said. "There were a lot of people he could have invited, too, [from] the Major Leagues. When he gave me the call the other day, it surprised me. This was one of my dreams to pitch in the Home Run Derby. It's the first, not the last, I think, for us."
Before taking his turn, Alvarez elicited suggestions from teammate and 2012 Derby participant McCutchen, who advised him to "take as many balls as you need. Get yourself where you feel like you're ready to swing. Don't go up there just trying to swing at the first pitch."
Alvarez complied, taking several pitches before he took his first cut. The first four balls Alvarez put in play were outs. The fifth -- a 376-foot shot to the right field -- got him on the home-run scoreboard. The left-handed-hitting Alvarez hit five of his six home runs to right. Four of those landed in the second deck.
His other blast traveled 456 feet to center. Alvarez's six dingers averaged a distance of 402 feet. His 461-foot homer was the third-longest hit in the first round.
"You have some jitters, obviously," Alvarez said. "But after it is all said and done, it was just a whole lot of fun. I was fortunate to be a part of it."
Joining the Pirates' four other All-Stars to root on Alvarez from field-side seats and in official orange All-Star jerseys was Alvarez's father. It was Pedro Sr. who moved his family from the Dominican Republic to New York when Alvarez was an infant and later took a job as a cab driver so that he could support his family financially while still having time to help his son pursue his baseball dream.
"It's very special for me, because Pedro grew up here and a lot of people still like him around here," Alvarez Sr. said afterward, with Pena translating. "He did this in front of the fans he grew up in front of."
Advancing to the Derby semifinals were Cespedes (17 home runs), Baltimore's Chris Davis (eight), Washington's Bryce Harper (eight) and Colorado's Michael Cuddyer (seven). Alvarez, Prince Fielder (five), David Wright (five) and Robinson Cano (four) were eliminated.
With the highest combined totals from two rounds, Cespedes and Harper moved on to the finals, which Cespedes won with nine blasts. In all, the A's outfielder hit 32 home runs.
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