Donegal's hopes of landing the Division One crown in the Allianz Football League have been dealt a blow.
Ryan McHugh has been ruled out of action for between three and four weeks after suffering an ankle injury in last week's drawn game with Monaghan.
The tendon problem will keep the 22-year-old out of Sunday's meeting with Mayo, and a potential League final the following week.
McHugh won an All-Star last year and was the Young Footballer of the Year in 2014.
Donegal travel to MacHale Park this Sunday knowing a win would guarantee them a place in the League final.