The match, part of Mexico's Bicentennial celebrations, is Spain's first outing since they beat Netherlands 1-0 in the World Cup final in South Africa a month ago.
"They're coming with the best they've got. We have to try to beat the world champions, imagine," Celtic defender Efrain Juarez told reporters on Monday.
"Why not think and dream that we can beat the world champions and dent their crown?"
Spain, who were due to arrive in Mexico City late on Monday, are unbeaten against Mexico in seven previous meetings with five wins and two draws.
Former Mexico coach Enrique Meza will be in charge of the team before handing the reins to Efrain Flores for friendlies against Chile on September 4, Colombia five days later and possibly another match against Uruguay.
The pair have stepped into the vacancy left by World Cup coach Javier Aguirre, who quit after Mexico's 3-1 second round defeat by Argentina in Johannesburg.
Only after the friendlies will the Mexican Football Federation name a coach to take charge of the team for the 2014 World Cup cycle.
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