"This had been building up inside of me for four to five months. By the time I got to it, I had been through all the emotional highs and lows, so I was prepared for it.

"Of course it is devastating that my rugby career is ending. After a few years where I had a series of injuries, I had got myself back into a position where I felt, physically and mentally, that I could play the best rugby of my career.

"Since I was 14 or 15 my identity has been forged around being a sportsman, a rugby player. Now, at the age of 29, a few years before I expected, the circumstances have changed."

Former Edinburgh number eight Denton suffered a blow to the temple during Tigers' league clash with Northampton Saints at Twickenham last October.

But his attempts to make a return to the game floundered before he was finally given the news by neurosurgeon Richard Sylvester this week that, for his own good, he should call time on his career.

In a separate interview with the Times, he said: "I have had this thing hanging over me for a long time now.

"Since the injury I have woken up every morning with pressure in my head and visual disturbances and not really knowing what is going on.

"Pretty much for that whole time I've been assuming that next week I will be better. Every time I tried to go through the comeback protocol, I'd fail. I've tried everything but nothing's worked."

Had he been fit, Zimbabwe-born Denton would have been in contention for a place in Gregor Townsend's Scotland squad for the World Cup in Japan.

And the number eight – who qualified for the Scots thanks to his mother Joy, who is from Glasgow – admits he will miss pulling on a dark blue jersey.

"The idea of never being able to run out in front of 70,000 people at Murrayfield again is not enjoyable," said Denton, who now plans to move back to Edinburgh with his fiancee Shelly and baby son Logan as he eyes a future in business.

"I so want the boys to do well [in Japan] and would so want to be there but that is not going to happen.

"It is important to me that I don't look back with sadness at what could have been, instead look forward and remain proud of what has been. There was a lot more I wanted to achieve. All of a sudden I am not able to do that."

Townsend paid tribute to Denton in a statement, saying: "We're really disappointed that someone who still had a lot to offer the game, both at club level and for Scotland hasn't been able to do that, but our first thoughts are with his health and his life beyond rugby and it seems to be the right decision to retire.

"As coaches we really enjoyed working with Dave over the years and we wish him all the best in life after rugby."