The Abu Dhabi Harlequins scrum-half says his decision is tinged with sadness as it means he will not get to represent the UAE national team.
Jonny MacDonald elated at Scotland call
Jonny MacDonald, the scrum-half who was born and raised in Abu Dhabi, has been called up to play for Scotland's sevens team.
The Cardiff University student will put his studies on hold for the next two weeks as he flies to Hong Kong and then Adelaide for the next two legs of the HSBC World Sevens Series with his new teammates.
MacDonald, who attended the British School al Khubairat and plays for the Abu Dhabi Harlequins when he is not studying in the UK, has previous experience of the IRB series.
As the playmaker in the defunct Arabian Gulf sevens side, he was a regular on the main field at the annual Dubai Rugby Sevens, and also shone at the 2009 Rugby Sevens World Cup.
"I was born in the UAE and grew up there but I have always aimed as far as I can," he said. "To be picked to play for Scotland in any sporting event, let alone rugby, which happens to be my favourite, is a great honour for me.
"Obviously, there is a tinge of sadness at not being able to play for the UAE, but that comes hand in hand with the elation [of being picked for Scotland]."
MacDonald, 22, qualifies to play for Scotland via his grandfather. He has also benefited from an IRB ruling which stated that players who represented the Arabian Gulf can choose to play for another nation if they fit the eligibility criteria.
As soon as he takes the field for Scotland he will become ineligible for the new UAE national team.
There is no doubt he will be a major loss for the national team, who start their HSBC Asian Five Nations campaign next month.
However, he was proposed to Scotland by the UAE rugby bosses, who felt his talent deserved exposure on the highest platform possible.
When the Gulf played their final tournament, at The Sevens in December, their coaches sought out their Scottish counterparts in order to recommend MacDonald to them.
"We don't want to lose him, but that is where he needs to be," Shane Thornton, the Gulf coach, said after the Dubai Rugby Sevens in December.
"He needs to step up to the big league. He would get more chances over there, would be playing with international players, and as we have seen over here, he is a class act."
MacDonald sent a video compilation of his performance for the Gulf at the sevens to the Scottish coaching team and was then invited to Murrayfield to train with the squad.
"It has not been intimidating at all. The guys have made it very comfortable for me," said the business management student.
"I won't lie: there is a definite difference in terms of quality between that and the Gulf, but that is good and hopefully it will rub off on me in some way."
Despite the unusual route he has taken to reach Murrayfield, MacDonald's new bosses are impressed by what they have seen.
"[MacDonald] has international sevens experience which is very positive," Graham Shiel, the Scotland sevens coach, said on the Scottish RFU's website.
"He'll learn a lot from the environment that we'll be in over the next couple of weeks and I'm sure he'll learn and do well for us." The trip to Hong Kong, which is the biggest event on the sevens series, has come at the right time in terms of studies, with the academic semester now breaking for the Easter holidays.
However, it coincides with the culmination of the university rugby season; MacDonald will miss Cardiff's meeting with their local rivals, Swansea.
"We have the Varsity Game coming up against Swansea at the Millennium Stadium," he said.
"Unfortunately, I'll miss that because we are away in Hong Kong. Every cloud …
"It is just coming up to the Easter break now, so exams are a while away so that is not a worry.
"I have coursework deadlines which I have just today managed to finish off, so it is coming at a very good time for me where I am able to put university on hold for a couple of weeks."