But his career stalled after his $20million transfer to German team FC Augsburg as an 18-year-old prospect, leading to a frustrating few years.
The striker has not started consecutive games for club or country in 18 months.
Pepi is behind Folarin Balogun in the race to lead the line for the USMNT.
But a crucial strike against Jamaica may make it hard for USA head coach Mauricio Pochettino to leave the PSV Eindhoven youngster out in future.
"I'm feeling ready to be the man, to be the starter," the 21-year-old said Tuesday.
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And two days later he scored the winner in a 1-0 CONCACAF Nations League quarterfinal, 1st leg triumph in Kingston.
Pepi was found by a Christian Pulisic through-ball in the fifth minute and kept his composure to settle a hard-fought contest.
It was his eighth strike of the season for club and country - and sixth in his last four starts.
Pepi has been stuck in a supersub role for PSV with veteran Luuk de Jong dominating the XI.
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"Obviously people are noticing the things that I'm doing whenever I come in as a sub, and it makes them say the word," Pepi told ESPN of his reputation for scoring off the bench.
"But at the same time, hearing that word, it makes me want to, I don't know, punch something."
"I'm at a point in my career right now where I'm ready," he added.
"I'm ready to either start, or to get more playing time. I feel like I've been showing that."
Pepi has begun to be handed more opportunities from the start for PSV over the last month.
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And with Balogun, Josh Sargent, and Haji Wright all injured, he now has his chance for his country.
Jamaica will be welcomed to St. Louis for the second leg Monday as Pochettino seeks a spot in March's semi-finals.
The 2026 World Cup on home soil is the main goal but Nations League glory would be a welcome bonus.
"Obviously it's easy to look ahead," Pulisic said Wednesday.
"The main objective right now is to beat Jamaica. That's truly the only thing on our minds."
"At the end of the day, we got the result," Pepi said after Thursday's win.
"And now it's time to go take care of business at home."