In 2025, Greig secured a tie for 12th place at the Swiss Seniors Open in July, finishing with a score of 201 (−9). In August, he achieved a 9th-place finish at the Grass & Co English Legends, posting a score of 212 (−7).
Greig joined the Legends Tour as a graduate of the 2023 Q-school – He would end his debut season ranked 8th in the Order of Merit having claimed runner-up finishes at both the Jersey Legends and the Legends Tour Trophy hosted by Simon Khan, he would also register top ten places – at the Irish Legends and the Vinpearl DIC Legends Vietnam.
A three-time winner on the Challenge Tour from 1999 to 2003, Greig learned to play golf in his hometown of Aberdeen under Banchory pro Doug Smart, who also coached Paul Lawrie.