Former Young Footballer of the Year Ryan McHugh will not play again this year due to a concussion.
The Donegal man will miss his club Kilcar's defence of their county title having sustained a second concussion of the year in a challenge game against St Vincent's recently.
Earlier this year McHugh suffered a similar injury in Donegal’s Allianz Football League defeat to Tyrone at Healy Park.
Kilcar will also be without 24-year-old McHugh's Donegal team-mate Patrick McBrearty who is sidelined with a knee ligament injury.
They face Naomh Conaill in the quarter-final of the Donegal SFC this Sunday.
"Ryan won't make it this year," Kilcar manager Barry Doherty told the Donegal Sport Hub.
"It’s a huge blow, of course it is. We’ve only had him for one league game all year and other lads will have to step up and we’ll need to get more out of them."