Mexico coach Miguel Herrera confirmed striker Giovani dos Santos was replaced at half-time against Trinidad and Tobago due to injury.
Reports emerged during the second half of Mexico's 4-4 draw with Trinidad and Tobago that Dos Santos had injured his right thigh, and Herrera told journalists after Wednesday's match that the LA Galaxy recruit would be sent for tests.
Oribe Peralta, who scored a hat-trick in Mexico's CONCACAF Gold Cup opening win over Cuba, replaced Dos Santos against Trinidad and Tobago and would be favourite to start in place of the 26-year-old in the quarter-finals.
"We will see how the situation of Giovani dos Santos is assessed and if I will need to make a change," Herrera said.
Galaxy announced the recruitment of Dos Santos before Mexico versus Trinidad and Tobago.
Mexico face Costa Rica on Sunday for a spot in the Gold Cup semi-finals.
