Allan has been named in the full Italy squad a little more than 100 days since he earned the last of 16 caps for Scotland's Under-20s. The under-20s are not Scotland's designated "second team" - the A team being that - so under International Rugby Board rules the 20-year-old Perpignan stand-off is free to make the switch to the Azzurri, his mother, Paola Berlato, being Italian.
As a result, Jacques Brunel, Italy's head coach, selected him on Tuesday for his 35-man squad for the Autumn Tests against Australia, Fiji and Argentina. Allan, however, has not yet played for Italy and his uncle believes if Scottish Rugby - through the vehicle of Edinburgh Rugby or Glasgow Warriors - were to help him secure his future, he could be wearing dark rather than light blue in the years to come. John Allan, who won nine caps for Scotland and 13 for South Africa between 1990 and 1996, said: "Ultimately, rugby is a profession, a job. I helped get him [Tommy] to Perpignan - where he has been competing for a spot with Welshman James Hook - to get some good, hard rugby under his belt. He has been doing well, but still doesn't have a contract. He needs a contract to secure his future for the next three years. In my eyes, whoever gets in there first, that's who he will play for. Scottish Rugby must find out what club he wants to play for, speak to Perpignan, and get him in there. For me they should have been in there a year ago."
Tommy Allan has been well-known to SRU coaches since joining the Exiles system as a teenager living in Henley-on-Thames. After the IRB Junior World Championships in France in June, Scott Johnson, Scotland's director of rugby, and his team, including Scotland head coach-in-waiting Vern Cotter, have been in regular contact with him.
That relationship continued until as recently as last Thursday when one of Scotland's coaching squad phoned him to get an update on his progress. During that call, it is understood Allan did not intimate a desire to play for Italy, but that all changed on Tuesday afternoon.
Tommy knew when he was growing up in Vicenza, Italy, that he had options over which country he could represent. Speaking in early 2012 he said: "My dad played a lot of rugby in Italy as did my mother, while my uncle earned caps for Scotland and South Africa, so I knew that I had ties to the three countries."
He then moved to England and played at Henley Hawks, RGS High Wycombe, London Scottish and Wasps. Tommy turned out for Scotland Under-17s in the Wellington Tournament in 2009/10 and then for the under-18s in France the following season before being pushed up to under-20 level at the start of the 2011/12 campaign following a move to Western Province in South Africa.
He won seven caps at under-20 last year and this year has played in all the under-20 matches in the RBS 6 Nations, scoring 16 points against Italy at Gala, and earning a further four caps at the IRB Junior World Championships in France.
The situation recalls Scotland's calling-up of the Wales Under-20 cap Steven Shingler for the RBS 6 Nations in 2012 only for the move to be blocked when the IRB ruled that the age-grade team were Wales' "second team" and that Shingler was therefore tied to that country.