Tim Brabants, from Surrey, has just got through to the semi-final of the 1,000m canoe at Eton Dorney - ready to defend his Olympic crown.
He came second in the first round of the sprint, having won three medals in previous games.
Brabants, who won gold in Beijing, needed surgery in 2010 after he ripped his right pectoral tendon doing bench presses in the gym.
Since then it has been a struggle to get back to peak fitness and the 35-year-old accident and emergency doctor admits it will be tricky to defend his crown.
Today he opens the canoe sprint competition in the men's K1 1000 metres heats at Eton Dorney, where he will be hoping to add to the success of the canoe slalom specialists who won gold and silver in the men's two man boat.
Brabants, from Walton-on Thames in Surrey, said: "It has been an uphill struggle to get here since my shoulder injury in 2010, with 2011 and the early part of this year being pretty much a write off.
"I am now just getting better and better and back to be where I want to be at this stage and I am as ready as I can be.
"I haven't written myself off, I am back on form now and I have got the experience from previous games, so I know I can handle the pressure side of it.
"When I sit on the start line I know I have given it everything I can, but there are a lot of talented athletes in our sport so it is going to be tough and with different winners at all the major races this season it shows the quality of the field."
If Brabants fails to strike gold, Team GB has another great chance in Ed McKeever, dubbed the Usain Bolt of the water.
McKeever, 28, from Bradford-on-Avon, is competing in the new men's K1 200 metre sprint. The trainee accountant is one of the favourites for gold, after winning in the world cup series earlier this year.
Liam Heath and Jon Schofield in the K2 200m also represent a great medal chance for Team GB, while Richard Jefferies, who was selected for the Olympics after making it through the Sporting Giants talent spotting scheme, will compete in the men's C1 1000 metres and C1 200 metres.
A medal for Jefferies, who only applied after his brother saw an advert in his local gym, is unlikely but given the success of Helen Glover in the rowing, also selected through the scheme, expectations will be raised.
In the women's K4, Jessica Walker, Rachel Cawthorn, Angela Hannah and Louisa Sawers compete for Team GB.
Cawthorn will also race in the women's K1 500 metres, while Walker will compete in the K1 200 metres. Sawers will be joined in the women's K2 500 metres by Abigail Edmonds.
The team's head coach Brendan Purcell said the preparations have gone well.
"We've had a really good pre-training camp. It was great environment to put the final touches to the preparations," he said.
"Everyone is getting very excited about being a part of the Olympics. We all went down to watch the rowing today and absorb the atmosphere. It was very inspirational to see the guys in the canoe slalom pick up their first gold. Everyone now can't wait to get out there on the water."