Young Burnley striker McCartan ruled out of U21 Euro qualifiers
The Clarets striker suffered the setback at an international training camp earlier this week and is now likely to be sidelined for up to eight weeks.
Clarets boss Eddie Howe said: “It’s a real shame for Shay. He was away with Northern Ireland for a few days and tweaked his knee.
“It’s a ligament injury but thankfully he has been lucky and won’t need an operation, but he will be out for around eight weeks and it’s a blow.
“However, he’s in good hands with Ally and our medial team and we look forward to seeing him in action again soon.”