Mexico star Giovani Dos Santos could miss semi-final

An adductor injury suffered in Mexico's draw with Trinidad and Tobago saw Dos Santos sidelined for the controversial 1-0 quarter-final win over Costa Rica on Sunday.

The 26-year-old warmed up before returning to the bench, and he may not be ready for Wednesday's clash in Atlanta.

We will have to keep working on him, see how he feels, Mexico coach Miguel Herrera said.

If he"s 100 per cent, then there"s no doubt he"ll go in. If he doesn"t, then he will not.

Herrera said Dos Santos was told to warm-up to see how he felt, but the LA Galaxy recruit "did not feel confident".

Mexico's win was secured in the 124th minute against Costa Rica as Andres Guardado converted a controversial penalty.

But, after again watching Mexico fail to take their chances, Herrera said it had been a worry heading into the Gold Cup.

"That has been our main concern since the beginning of the tournament, to be effective up front," he said.

"Unfortunately we haven't been able to be as effective as we would want to."