Houston outfielder Carl Everett was ailing, and Hunsicker summoned a former first-round pick who was in his second season at Triple-A New Orleans and only two years removed from hitting 41 home runs to lead Rice University to the College World Series.
"I was like, 'Oh my gosh!'" Berkman said. "I had to spend the night in Arizona and fly the next morning. I didn't get a very good night's sleep at all. My wife [Cara] was out there with me and we flew the next day, and I showed up at the Dome at 1 o'clock, which might be the earliest I've ever gotten to the field."
The date was July 16, 1999, and the Astros were playing the Detroit Tigers in the Astrodome. Houston fans couldn't have envisioned at the time they were about to witness the birth of one of the franchise's greatest players. Ten years later, Berkman is considered one of the top three offensive players in club history.
His 306 career home runs are tied with Ruben Sierra for sixth all-time among switch-hitters, and his .558 career slugging percentage is the highest all-time among switch-hitters (Mickey Mantle is second at .557).
He played left field, center field and right field before settling permanently at first base last year. He is a five-time All-Star and five-time team Most Valuable Player, but he still can't help but chuckle at how his illustrious career started.
"It was just surreal," he said. "I was almost lightheaded from the lack of sleep, and the excitement made me almost giddy. I didn't think I was going to play because I had just flown in, but I'm sitting there on the bench and sure enough, [manager Larry] Dierker said I was going to pinch-hit for the pitcher."
The pitcher, Scott Elarton, was due up third in the seventh inning of a 1-1 game, and, as luck would have it, the first two batters reached. Dierker wanted Berkman to bunt, but the eager rookie was in the batter's box too quickly to get the message.
"The first pitch I saw from Justin Thompson, who was this left-hander with a great big ol' curveball, looked like it started way up high and ended up low on the inside corner for a strike," Berkman said. "I just remember thinking, 'If that's a Major League curveball, I'm going to have trouble because that's nasty.' I ended up hitting a sharp grounder, but I hit into a double play and killed the rally."
Berkman was sent back to New Orleans before rejoining the Astros for good later in the season. He was sixth in the NL Rookie of the Year voting in 2000 and made the All-Star team for the first time and was fifth in NL MVP voting a year later. A star was born.
Berkman and franchise icons Jeff Bagwell and Craig Biggio dominate the Astros' offensive record books, and Berkman appears on his way to breaking some of their records. He ranks third all-time in runs scored, walks and extra-base hits, second in home runs and first in career batting average.
"I can say I'm happy to have accomplished the things I have so far, and hopefully I have a few more good years left in me," said the 33-year-old Berkman. "When you're playing you're not saying, 'Oh, I need to do this and end up here and I'd like to hit this many home runs or drive in his many so I can be ranked first or second or whatever it is.'
"For me, when you get to a certain point in your career, the numbers individually are nice, but you'd just like to win. It's a lot more fun when you win. We still haven't won a championship here and I would love to do that. I'm more proud to have been part of the first World Series in the history of the organization  than any of the individual accomplishments.
"Not that I don't enjoy those individual accomplishments because there's a big individual component to the game of baseball. It's neat to be recognized and look at your name and see that in most offensive categories it's me, Bagwell and Biggio. That's pretty cool. But as far as doing stuff to cement my legacy, I'm not thinking about that."
Berkman, who has one year remaining on the six-year, $85 million deal he signed in 2005, doesn't envision himself playing into his late 30s, or playing just to pad his career totals. Earlier in his career, he said he wouldn't play beyond his current contract, but he appears more open to a possible extension.
"A lot of it has to do with if I'm healthy and feeling good and still productive," he said. "I'm 33 this year, and you could play until you're 40, but I don't know I will. At some point it's going to be a year at the time, and we'll take it form there."
Berkman will certainly be remembered as one of the greatest players in Astros history, but his place in baseball history isn't quite as clear. Despite his impressive career average and slugging numbers, he may not reach the 500-homer and 1,500-RBI plateaus considered by many to be Hall of Fame benchmarks for sluggers.
"I'm afraid I'm probably going to be a borderline guy if I stay healthy and continue to be somewhat productive, as far as compared to what I've been in the past," Berkman said. "If you project another five or six years, my numbers will get to the point where people will be like "Hmm, you know, possibly.' Then you just have to hope enough of the sports writers like you."
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.