Growing up in El Paso, Texas, the United States-Mexico soccer rivalry was always appointment viewing in Pepi's household.
"[It was] a special feeling having my family besides me always rooting for the game," Pepi said Tuesday. "It was rooting for Mexico back then."
Following Pepi's international commitment to the USMNT in August, it's even more important and, of course, the family allegiance has changed.
The 18-year-old FC Dallas striker said he'll have about 10 family members in attendance at TQL Stadium in Cincinnati as the United States and Mexico renew their rivalry.
He said he can already anticipate what it will be like to hear the national anthems.
"It's going to be a special feeling," he said. "Having my family in the stands having me with the U.S. jersey on -- I feel like I'm going to get some goosebumps for sure. It's going to be that feeling where I'm going to be very motivated for the game, and I'm going to be prepared for it."
Pepi's meteoric rise to the top of the United States men's national team striker depth chart over the past two months has been among the most important developments as the team started World Cup qualifying.
He scored three goals in his first two appearances and is expected to receive the bulk of the minutes this window as the United States hosts Mexico before traveling to Jamaica for a game on Tuesday.
Pepi scored 13 goals in 31 league games this season, topping Dallas and 12th overall in Major League Soccer.
"He's taken his opportunities really well," United States midfielder Kellyn Acosta said. "He's showcased well in MLS, then coming here in the national team he's been great, scoring a bunch of goals being a force up front.
"I think he's a guy that's pretty level headed despite everything going around around him. He's done a great job of being being confident and being a quiet assassin on the field."
Through six matches, Mexico (14 points) sits three points ahead of the United States (11) in the CONCACAF standings, with Canada in third with 10. The top three teams at the end of 14 matches will automatically qualify for the 2022 World Cup in Qatar.
After beating Mexico twice in the summer -- in the finals of both the Nations League and Gold Cup -- Acosta added that the USMNT is confident headed into the match, especially considering the expected favorable crowd in Cincinnati.
"We're expecting to come out aggressive and being decisive as well," Acosta said. "And I know they're going to try to match that intensity. Being in a pro-U.S. environment is definitely huge for us. And each home game is a game that has to be a must-win in order to go into that game with that mentality."