Due to their first team's engagement at the ongoing Fifa Confederations Cup in Russia, El Tri were forced to assemble a second-string side for the Ghana encounter, with Paez leading the side in the absence of Juan Carlos Osorio.
In the end, the 1986 World Cup quarter-finalists walked away 1-0 victors at the NRG Stadium in Houston, Texas thanks to Elias Hernandez's 32nd minute penalty after John Boye fouled his marker.
"We had a very challenging match," Paez said after the game.
"It is not every time we face an African team with 90 per cent of fast players and Mexico competed. It was smart.
"Sometimes we competed equally with shots and corners.
"It was really demanding, that's why we made a lot of substitutions.
"Fortunately, we don't have any casualties by the way of muscle [injury] or overload because the players are in the preseason."
Wednesday's game was the third meeting between Mexico and Ghana at senior level, the former having also won both preceding encounters.
At the Gold Cup, which runs between July 7 and 26, El Tri will play in Group C alongside El Salvador, Curacao and Jamaica.
Paez's outfit take on Paraguay in another friendly fixture on July 1.