Atlanta United attacker Ezequiel Barco will be out four-to-six weeks with a right quad strain, the MLS club announced on Wednesday.
Barco, 18, suffered the injury during training on Tuesday.
Barco sealed the largest transfer in league history last month when he moved from Argentine giants Independiente to Atlanta for $15 million, plus a possible percentage of any future transfer depending on the date.
Atlanta will open the 2018 season this Saturday against the Houston Dynamo.