Whether it's in the charged atmosphere of an Old Firm derby, or gracing the game's elite competition, the Champions League, McDonald has never looked fazed.
He told tribalfootball.com: "Yes and No. By that I mean I played in some big games very early on in my career. People forget that I played in a Under 17 World Cup final against Brazil when I was 16. Then I made my debut in the English Premier league for Southampton at 18.
"I think alongside the World Cup, then playing against the world’s best players in the Champions League is the pinnacle of world football. To play against Ronaldinho, Maldini, Rooney, Ronaldo, etc how can you not be delighted?!"
After winning a championship in his first season at Celtic, McDonald could be on for a stunning Treble this term. The diminutive forward says winning things will never get routine.
"It’s not routine. Some of the world’s greatest players have played all their careers and never won any trophy. For me to have two medals already makes me very humble and certainly appreciative of the opportunity I have at Celtic. I will never take that for granted.
"Celtic is about winning. Titles are to Celtic what survival is to many small clubs. SPL titles are the gateway to Europe and to appeasing the 10,000,0000 fans Celtic has around the world. Everyone at Celtic from the chairman Mr Reid and the majority owner Mr Desmond right through to our celebrity supporters like Billy Connolly and Rod Stewart through to our support staff and fans…we all want to win and fly the Celtic colours!
"Celtic is a force in Europe. Our Club is a former winner of the Champions League against Internazionale of Italy and that is a legacy we all carry. When Celtic arrives in a European city to play against the home team everyone knows that we are coming. We have one of the biggest and best behaved travelling supporters in world football and everyone here is there to win!"
McDonald concedes it could have been all so different if not for a chance trial at Motherwell.
The forward was a free agent at the time and had failed to impress at Dundee United. The then Well boss Terry Butcher gave him an opportunity and the rest is now history.
There has been talk that his move to Tannadice was scuppered by a slow cross-country time caused by a call of nature!
"Nah, I think that is what has now been thrown around but the reality was that when I went to Dundee United I was really unprepared from a fitness and confidence point of view," laughed McDonald.
"I always had belief that I wanted to go as far as I could with football and as most youngsters I dreamed of playing for my Club that I followed. In my case Celtic was the Club my family supported and as a young kid I dreamed of one day wearing the famous Celtic shirt. Now I am living my dream playing for my Club."
"Motherwell played hard ball. The reality was that I had been doing well at Fir Park for the previous two seasons and in the summer I went public by saying I wanted to move on to further my career. That pretty well alerted other Clubs while at same time upsetting the Motherwell faithful.
"But in the January window Rangers made a last day offer for my services that Motherwell FC ultimately rejected. That left me upset but I still worked hard for the team and continued to score goals. Then Celtic came in for me and Motherwell got a nice fee which I was very happy for them to do so."
McDonald always kept his nerve while negotiations were rolling along and credits his outside influences for keeping him in-check.
"Off the field my Dad is the person who got me into loving the game as much as I do now. From the age of five he was my first coach and has been so close to me in my football. Even when you think that for 10 years he was in Australia and I was in UK, his regular chats would offer me so much support as did my Mum and brothers," says McDonald.
"My agent Lou Sticca and a former Rangers legend in Dave McPherson have steered me through the tough times to where I am now. On the field, firstly my manager Gordon Strachan has been wonderful for me, even though many years ago at Southampton he cut me loose! I rate all the support staff at Celtic for the help they have offered me and the return of Neil Lennon has been great for me too."
McDonald is in Australia this week preparing for their critical World Cup qualifier against Uzbekistan. Victory could seal a World Cup place for the Socceroos and McDonald would love to thank the local media and fans for the new recognition he's receiving with big performance against the Uzbeks.
"I am in the media heck of the lot in the UK," smiled McDonald, "but since moving to Celtic the Australian media have not left me alone. In fact I do more interviews for Australian papers and TV than I do for the Scottish press."
And no doubt he'd would welcome another round of interviews if he was to score the goal that sent Australia to South Africa.