"A lot has to go well and fall into place. I have to get my fitness and my boat feel back and make sure I'm mentally where I want to be.

"The end point would be going all the way through to Rio, but I'm not making a commitment to that one just yet."

You just sense that Redgrave, who said before the London 2012 Olympics that Grainger, having taken three successive Olympic silvers, was the rower he most wanted to win gold, would have encouraged her to heed what she described this week as her continuing "hunger" for the sport.

Redgrave, mentioned earlier this month on Grainger's Facebook page after nominating her ice bucket challenge for a Motor Neurone Disease charity, would surely be the last person in the world to pour cold water on her dreams of returning to the Olympic arena.

Steve Redgrave pictured at the 2000 Sydney Olympics after winning his fifth Olympic rowing gold. Has he advised Katherine Grainger to seek a fifth Olympic medal in Rio?
©Getty Images

As Grainger put it herself on her most recent Facebook posting:

"So it's time to return to the boat and test the waters (literally). I've missed it, I love it, I want to see if I can be good at it again. No guarantees, no promises, but a start. Many people have said it's a risk, but in the words of Neil Simon the playwright 'If no one ever took risks, Michelangelo would have painted the Sistine floor'."

As you might imagine, Grainger - a proud Glasgow-born Scot who celebrated her Olympic medal with a tartan scarf around her neck - has hardly been idling in the interim. Among the things on her ticked list were running the Virgin London Marathon, working for the BBC at the recent Glasgow 2014 Commonwealth Games, and earning her PhD in homicide at King's College, London. She has since been made a fellow of the University.

But while her 30-year-old fellow champion Watkins, who gave birth last year to a son, has ruled herself out of Rio 2016, Grainger has, after much introspection and debate, taken a different course - although it is, of course, a familiar one also.

Even a year ago, Grainger appeared to be hearing the boat sing its siren song once again as she became involved in a women's eight which included Watkins and other GB Olympians from the 1992, 1996, 2000 and 2004 Games, most of whom had retired.

"It was the only thing I did rowing-wise," she said. "And it captured my love for it all over again.

"It reminded me how lovely it is being with fellow rowers and how at a basic level, taking away the excitement of competing at an Olympics, rowing is a fantastic sport to be part of."

That crew won the Masters pennant at this year's Women's Eights Head of the River Race (W8HoRR).

Recently crew member Gillian Lindsay who competed with Grainger in the quadruple sculls crew which took silver at the 2000 Sydney Olympics, told me that the quadruple Olympic medallist had been one of the moving forces in suggesting the crew should challenge at the impending Head of The Charles regatta in Massachusetts - the world's premier two-day rowing event which will have its 50th running on October 18 and 19.

Katherine Grainger (second right), pictured after winning silver in the quadruple sculls at the 2000 Olympics along with Gillian Lindsay (second left), with whom she has rowed recently at Masters level, and sisters Guin (left) and Miriam (right) Batten ©Allsport/Getty Images

"The idea and suggestion was aired by Kath G and Kate Mac [MacKenzie] in Hudson's cafe after we had just raced the W8HoRR," Lindsay said. "It was clear KG and KM were game and when the proposal to keep the crew going was put to the rest of the crew the answer was obviously a resounding yes.

"It's lovely that there may well be an interest in our crew, but the only reason for originally pulling a crew together was for fun and enjoyment and to remind ourselves what it's like to row in a really good crew.

"There's a buzz when we're together and a mutual respect for all that we have achieved. For example rowing with Kath Grainger again has been great fun but she's so grounded and she too has said on several occasions just how much fun she is having in the eight."

Now, it seems, Grainger is reviewing the possibility of yet more fun - albeit soul-grindingly hard-working fun - in another boat.

Muhammad Ali, multiple world boxing champion and complex human being, pictured in 1972, knows what makes a true champion ©Getty Images

While she has taken her time over the decision to put herself on the line one more time, her mother, Kath, was less circumspect in the wake of her daughter's emotional victory on the Eton Dorney course two years ago as she readily suggested to the media that said daughter would follow her mentor Redgrave by continuing to a fifth Olympics.

"I overheard my mum saying that," Grainger noted with a laugh at the time. "I think she's enjoying the crowd stuff too much."

But maybe her mum knew something Muhammad Ali also knows.

"Champions aren't made in gyms," Ali wrote. "Champions are made from something they have deep inside them-a desire, a dream, a vision. They have to have the skill, and the will. But the will must be stronger than the skill."

Mike Rowbottom, one of Britain's most talented sportswriters, covered the London 2012 Olympics and Paralympics as chief feature writer for insidethegames, having covered the previous five summer Games, and four winter Games, for The Independent. He has worked for the Daily Mail, The Times, The Observer, The Sunday Correspondent and The Guardian. His latest book Foul Play – the Dark Arts of Cheating in Sport (Bloomsbury £8.99) is available at the insidethegames.biz shop. To follow him on Twitter click here.