Karl Lacey has been ruled out of Donegal's All-Ireland qualifier clash with Galway on Saturday because of a knee injury.
The four-time All Star defender suffered the injury during the first half of the Ulster final defeat by Monaghan.
A scan has confirmed slight ligament damage, ruling him out of the Round 4B qualifier in Croke Park.
"It's a huge blow because he had started the Ulster final very well, scoring a point and setting up another, and was in great form," said Donegal manager Rory Gallagher.
“There is slight damage to the outside of the knee, but we’ve known about it since the day of the (Monaghan) game.
“It requires rehab but no surgery and is similar to the injury Darach O’Connor had a while ago.
“He wouldn’t be out long-term but he is not available for the Galway game, which is all that is important at the moment.”
Gallagher confirmed speculation that Michael Murphy and Paddy McBrearty both carried slight knee injuries into the Ulster final - but insists they are both fully fit for Saturday's back-door tie.
“People read too much into things,” he insisted.
“Michael had a slight knock and Patrick got a bang in the Ulster semi-final against Derry, but they are both fine and trained with no problems at all at the weekend.”