Irish swimmer Daniel Wiffen has shown a “relentless ambition” that puts an Olympic medal well within his grasp, his former swimming coach has said.

The 23-year-old from Magheralin, Co Down, who holds the world record in the 800m freestyle, will compete in the Olympic final just after 8pm tonight.

He is considered one of Ireland’s greatest gold medal hopes at the games, where he could follow bronze medallist Mona McSharry onto the podium after her stellar performance in the 100m breaststroke final last night.

Stan Sheppard, a coach at Lisburn Swimming Club, where Daniel and his twin brother Nathan honed their talents, said the Olympian has always had a fierce, competitive drive that has now brought him within reach of a medal.

Mr Sheppard had taught both boys to swim some years before they joined the club in 2012, something he had not realised until they came to him and told him how they remembered those early lessons.

“Daniel was always very confident and ambitious, he has always backed himself and he has always been a worker,” said Mr Sheppard.

“He probably said to me when he was a kid, ‘I’m going to swim in the Olympics one day, I’m going to break a world record,’ those sorts of things.

“He would have said it and it might have been a wee bit tongue and cheek, but he has always had this relentless ambition to improve and be better and be the best. He set himself up for what might seem like unrealistic tasks but he would go after them with a steely determination that is very rare.

Daniel Wiffen holds the world record in the 800m freestyle. Photo: PA

“He definitely does have the mentality of someone who could be an Olympic champion, there is no doubt about that.”

Mr Sheppard said children watching the Paris Olympics at home will now be looking up to Wiffen – and bronze medallist McSharry – and see the success they have found in swimming.

“It’s tangible. The kids can see these people that live and breathe on the island of Ireland, who spent their formative years here and were able then to bridge across into high performance centres and be world-class athletes,” he said.

Wiffen is well-placed to earn a place on the podium, with final preparations ensuring that he is in a position to “deliver the best race possible” in the pool in Paris.

His head coach at Loughborough University, Andi Manley, said Wiffen has studied the type of race his rivals will swim, and they have covered “all the ‘what if’ scenarios” to ensure he has reached peak performance.

“Anything can happen, but in terms of what we’re focusing on, it’s just going to be delivering the best race possible for him,” said Mr Manley.

“We know how his rivals will swim it. We’ve been talking about that a lot over the last 18 months, in terms of all the ‘what if’ scenarios, and how to go about that. But I think he’s at a level now where he shouldn’t be fearful of anyone.

“We’ve done the work and he’s ready to go and swim real fast. And we just need it all to happen in that seven and a half minutes on the night.”

An occasion like an Olympic final is rare, an event so filled with emotion, pressure and expectation that many athletes can allow it to get the better of them.

Speaking on his way to Paris to watch Wiffen attempt to take home a medal, Mr Manley was confident the swimmer will “step up” in the arena, with a walk-out in front of 15,000 spectators “all adding to his performance rather than taking away”.

“It has been phenomenal. He has just consistently gotten better year-on-year,” said Mr Manley. “He has momentum coming into this, he is a guy on an upward trajectory and it has all been part of our plan with the goals we have set along the way.”