Donegal manager Jim McGuinness believes his team can improve after Saturday's 2-13 to 0-9 win over Derry in the Ulster SFC quarter-final at Ballybofey.
"It was not that impressive as a performance - we did a lot of things well in spells and have work to do for the semi-final," said McGuinness.
"It was a home game, we came in here as favourites and the boys had a bit of nerves in the first half.
"We got our rhythm going in the second half and it opened up a bit more."
Patrick McBrearty was among Donegal's top performers, just a day after the 18-year-old student finished his exams.
"He came into the squad at 17 and he has it all physically and mentally," added McGuinness.
"He fatigued a bit near the end but he still played very well."
Derry boss John Brennan said "everything went wrong" for his team in the derby encounter.
"We were just full of indecision and once they got the first goal they became confident," he added.
"We should have done better and I'm so disappointed for the Derry people.
"Our players were passing straight to Donegal players - we made repeated mistakes.
"If you prepare a team to the best of your ability then the result shows either the team was not properly prepared, or have we the personnel good enough to compete against Donegal?
"If that is the case then there's a massive rebuilding job to be done in Derry."