Vela back Argentina clash
Vela went off in the first half against France last week with a leg problem and missed the 1-0 loss to Uruguay on Tuesday which secured Mexico's place in the first knockout round.
The 21-year-old adds pace to coach Javier Aguirre's attacking side, which will have to be at its very best against Diego Maradona's rampaging team who recorded three wins in the group stage.
Sunday's match will be a repeat of a second round game in the 2006 World Cup which the South Americans won 2-1 in extra time, but Mexico midfielder Israel Castro was adamant Argentina did not have the upper hand over their Latin American rivals.
Nor was he worried about how they might deal with Argentina's dazzling Lionel Messi.
"Man for man I don't think Argentina have an advantage," he said. "I see a united team but we're not thinking about any one player."