Grevemberg, who previously served as the chief executive of the Glasgow 2014 Commonwealth Games Organising Committee before moving to the CGF, is one of two external custodians to sit on the Board, as part of governance reforms.

He is to be joined by Cheryl Black who has worked as a customer service director and non-executive director with the National Health Service (NHS), EDF Nuclear, Telefonica and Scottish Widows.

The American served as the Glasgow 2014 chief before his seven-year stint at the CGF; and announced his departure in February 2021.

In April of that year, he joined the Centre for Sport and Human Rights as its chief innovation and partnerships officer.

He was regarded as an advocate for integrating human rights standards into the CGF during his tenure.

Grevemberg and Black are to sit on the Board with chair Lorne Crerar, SRU President Colin Rigby, former President Ian Barr and vice-president Keith Wallace.

"It is a true honour to be selected to serve and support the Scottish Rugby Union family during this critical and exciting time in the sport's transition and growth," said Grevemberg.

"I look forward to working with my fellow custodian directors and the broader leadership across the Scottish Rugby landscape as we continue to enable our athletes and teams to inspire and make Scotland proud now and well into the future.

"I'm particularly looking forward to welcoming more people into the sport, whether as players, officials, volunteers or supporters at the community level and beyond."

Two more external custodians - from the Scottish rugby community - are to be appointed in 2023.