The Four Masters clubman takes over from Declan Walsh for the province decider, however it is bad news for Neil Gallagher who will miss a second successive Ulster final due to injury.

A chipped ankle saw him sit out last summer's 2-18 to 0-13 final defeat of Down and strained knee ligaments have ruled him out of the clash with Monaghan. Ryan Bradley will instead partner Rory Kavanagh at midfield, with David Walsh coming into the half-forward line.

Lacey appeared as a second half substitute in Donegal's opening Ulster Championship win over Tyrone in May, but the knee injury kept him out of the subsequent semi-final victory over Down.

Donegal manager Jim McGuinness confirmed his team line-up at a Club Tir Chonail event in Letterkenny last night, and he was clearly pleased to have the influential defender back on board.

"It's a huge lift to us," he said.

"Karl has been working very hard to get his fitness back with the strength and conditioning coaches in Dublin and he has made great strides."

Weighing up the challenge posed by Monaghan as his side chase an 11th successive Ulster Championship win, McGuinness added: "We are on red alert. It will be a very tough battle. Hopefully the team we have put out will be strong enough to do the business.

"Monaghan will be very hungry. I feel the players are ready for the challenge and they look the sharpest they have been since the All-Ireland final last year."

If Donegal triumph afternoon on Sunday, they will join Antrim, Armagh, Cavan and Down as the counties who have won three Ulster SFC titles in-a-row.

DONEGAL (SFC v Monaghan): Paul Durcan; Paddy McGrath, Neil McGee, Eamon McGee; Anthony Thompson, Karl Lacey, Frank McGlynn; Ryan Bradley, Rory Kavanagh; Mark McHugh, Leo McLoone, David Walsh; Paddy McBrearty, Michael Murphy, Colm McFadden.