Despite the 3-1 scoreline and two first-half goals for man-of-the-match Aiden McGeady, McDonald, who hit Celtic's other goal, admitted the visitors should have added to their tally.

McDonald said it was good to get his first of the season in the opening match, but also conceded the visitors should have been more "ruthless".

"It's one out of the way already," he said."We should have had five or six."

McGeadty agreed.

"In the first half we played some good football - it could have been five or six," he told Sky Sports 3.

"It was a disappointment not to score more goals in the first half."

Celtic manager Tony Mowbray believes "some good and some bad" came out of the match.

"We were frustrated at half time," he said. "We should have had one or two more goals."

Dons midfielder Sone Aluko pulled a goal back in the second half, and manager Mark McGhee was fairly upbeat despite the loss.

He said: "There was some good in our performance today. I'm not going to get too upset. Celtic are a good team and they played well in the first half.

"We have lost a game to a good team."

Looking ahead to Celtic's Champions League clash against Arsenal at Parkhead on Tuesday, Mowbray said: "It will be a great game.

"I am very, very respectful of Arsenal. It's a big, big ask for us."

McDonald added: "We believe we can do the business."