Uruguay captain Diego Lugano has been ruled out of the key Group D clash with England due to a knee injury.
The combative central defender is out with pain in the left knee, which is not responding to treatment.
Lugano, 33, did not take a knock to the knee and scans have also failed to detect the cause of the problem, but he does not appear to need surgery, the AUF said.
His withdrawal is another blow to Uruguay, who have already lost right back Maxi Pereira through suspension after he was sent off in the 3-1 loss to Costa Rica.
But they are expected to welcome back Liverpool striker Luis Suarez, who has been out after knee surgery, for Thursday's game where defeat is likely to spell doom for either team.