[3] Fergusson was assigned Ayr in the Pro draft for the Scottish Premiership sides from Scotland 7s for the season 2017-18.

Fergusson was named in the Glasgow Warriors squad to take on the French side Clermont in a pre-season game[11] in the 2015 Auvergne Challenge in Issoire.

In November 2015, he was loaned to London Scottish by Glasgow Warriors to gain more experience of playing professional rugby.

On 7 April 2016, this deal was made permanent, and Fergusson officially signed for London Scottish.

[16] On 7 October 2021, it was announced that Fergusson had signed for the Warriors for a third spell with the club, to begin in January 2022 when his commitments end with the GB 7s team.