Burnley striker Jason Gilchrist will miss several months after suffering a broken ankle in the friendly at St Mirren.
The 20-year-old was stretchered off after falling awkwardly in the game at St \Mirren Park on Wednesday afternoon.
And scans have since confirmed he has a fractured fibula that will require an operation.
Burnley manager Sean Dyche confirmed: “It’s a real shame for Jason. But he is good hands and he’ll have an operation in the next few days and be looked after well by our physio team.
“Naturally, he will be sidelined for a period of time, but we wish him well in his recovery.”