"Sean's confidence in me and a bit of game time . . ." he said. "Game time brings anybody on. The chance to test myself and play week-in, week-out built up my confidence. Sean and Shade had so much confidence in me, it built my confidence up."
The men in question are Sean Lineen, since sacked as Glasgow Warriors' head coach and Shade Munro, his assistant who remained after the coup in which Lineen was ousted last season.
Grant was released by Edinburgh in the summer of 2010 by Rob Moffat, who had been Robinson's assistant coach at Edinburgh before taking over from him in 2009. However, the pattern of his career there was set in the two seasons that Scotland's current head coach was in charge, during which the prop made just two starting appearances.
Given the importance of talent assessment and nurturing within a coach's skill-set, Grant's experience only seems to underline the questions raised about some of the decision-making in Scottish professional rugby this year.
Lineen shifted him from tighthead prop, where he admits to having struggled, to loosehead, where he made 37 appearances for Glasgow in the next two seasons, resulting in his international debut last summer.
His solidity was such, helping Scotland win three summer Tests, that he is now preferred to 12-year, 64-cap veteran Allan Jacobsen for Sunday's televised Murrayfield encounter with New Zealand.
Furthermore, he may also have to revert to tighthead if Geoff Cross, who has not played since suffering a head knock in Munster two and a half weeks ago, either has to drop out or is injured in the course of the match.
Grant admits the challenge is considerable, but he is ready whatever happens and as he admits to having thought his chances of being a home player at Murrayfield again, let alone playing there for Scotland, were over just two years ago, his excitement is understandable.
"I've said before that when I was coming to the end of playing with Edinburgh, I was probably thinking about not playing rugby again professionally, but I'm so happy and grateful that it's worked out this way. I'd have said at that time I wouldn't have had a hope [of this]," he said.
"I've sat in the stands for a lot of Scotland games and watched the players run down the tunnel with real pride and excitement. Now, it's my turn and I'm really looking forward to it."
As to his treatment at the hands of Robinson when he was his club coach, he is understandably diplomatic. "I learned a lot and at that point I probably wasn't quite ready, so you know . . . no grudges," Grant added with a grin.