Donnelly states that have squad have worked hard since the loss to Down and are keen to make up for that defeat when they take on their neighbours in this make or break encounter although the former Fermanagh player is quick to stress that Fermanagh, like Cavan, are still a work in progress.
"There has been a good response from the players since the defeat to Down and I suppose we always expected to get that from them as their attitude has been good all year. We all realise that we are a work in progress and we're not the finished article. We know we need to improve and the players realise that and know they need to work harder. But in fairness to them they have knuckled down since the Down game and focused on the next game," he said.
Fermanagh's plans for the game against Down were badly hit in the weeks leading up to the game with the loss of players to injury and then the dismissal of Daryl Keenan early in the contest.
And Donnelly is pleased that the side have the chance to put right the wrongs of the clash with Down when they face Cavan on Sunday.
"That was maybe the most frustrating game about the game in that you felt slightly cheated that you didn't get a proper crack at it. With the sending off, our whole game plan went out the window," commented Donnelly. "But that's the beauty of the backdoor, you get a second chance to put things right and that's what we'll be trying to do on Sunday. It will be a test for the boys because they are coming up against a team who have plenty of confidence and have won Ulster medals over the last two years at U21 level but I have no doubt that they will meet it head on."
Indeed, Cavan's underage success has marked them out as a team to watch over the next few years.
"It is a good yard stick for us," commented Donnelly. "We're aware of Cavan, they are an up and coming team and they would look on themselves as a work in progress as well, especially with a relatively new manager. They would have went away and worked hard for the next round after losing to Donegal and I think the confidence they gained in winning those two Ulster U21 titles against Tyrone will stand to them. They will be confident going in against us. It's two very evenly matched teams and it will be a tough championship game," he stated.
Midfield is set to be one of the decisive battles on the pitch on Sunday, and Donnelly says it is an area that Fermanagh have been working on with the knowledge that Cavan are particularly strong in the middle third.
"Midfield is a vital area on the pitch and if you win your primary possession, normally the team that does that wins games. It's an area we have been working on and we know it's an area where Cavan are extremely strong. Physically they are very big in Givney and McKiernan and we know Cavan would see that as one of their strengths."
However, he believes that a good crowd can be expected at Brewster Park and he is hopeful that the players will give the supporters something to cheer about.
"It is great to have a home draw. We felt that the Fermanagh fans wanted to get behind us the last day but just didn't get the chance with the game going flat after the sending off but after we got the goal in the second half again you could sense the crowd wanting to drive us on. In terms of it being a derby game it should bring out a good crowd and the players will have no problem getting up for a game against Cavan because of the close proximity between the counties and every game against Cavan in the last few years has been close," he said.
And he states that the players are eager to put a run together in the qualifiers and end a barren four year spell that has saw the county fail to produce a victory in the backdoor.
"We had a good record at the start of the qualifiers and the players at that time enjoyed it. It brings confidence and breeds confidence in a squad to be winning championship matches, there is no better feeling than that. We are aware as a county that we have not done ourselves justice the past couple of years but the players are focused and are keen to do well in the Fermanagh jersey and represent it well. Hopefully that will bring a good result."