In his first season with the Scottish giants, McDonald, 24, scored 31 goals in 32 matches to finish 10 clear on top of the league's goal scoring list.
"It was a fantastic finish to the season for. That's what you work hard all season for, the championships and success," McDonald said.
"I'm absolutely over the moon to have done that. It also means we automatically qualify for the Champions League, so that's a fantastic prospect for myself and the rest of the players, to get another chance to play against the best players in the world."
With his club future bright, McDonald has turned his attention to carving out a future with the national team.
"I've not had too many games for other reasons or not, with injury and club commitments," he said.
"But now it's a great opportunity for me to sink my teeth into it and try to get into the starting eleven and make it my own. Obviously with Josh (Kennedy) not here it will give me more opportunity to go and play and put some ideas into the manager's head."
With Socceroos coach Pim Verbeek yet to finalise his side, McDonald said he preferred not to be played as a lone striker in Sunday's match, but added he would do whatever job was asked him by the Dutchman.
"In recent times, especially in the Champions League away from home with Celtic I played up front on my own and learnt a lot more, experience-wise playing in that position on my own. I'd be more than happy to do that job if called upon for my country."