Also withdrawing from the squad this week is Scarlets back Morgan Stoddard, who has picked up a hamstring tear which will see him in rehabilitation for two to three weeks.
"Bradley suffered a ligament sprain to his ankle during training on Tuesday and subsequently has been pulled out of the match against the Pumas this weekend," said Wales physiotherapist Mark Davies.
"He will remain in camp and his progress will be reviewed early next week before a final assessment is made.
"Morgan has a grade one/two tear to his hamstring and he will now be in recovery and rehab for a period two to three weeks."
The Wales management team will take a decision on whether or not to call any further personnel into the Invesco Perpetual Series squad early next week.