Two 19-year-olds, Magnussen and James Roberts, dominated the men's 100m freestyle at the national trials, securing the prized individual spots on the Australian world championship team.
The confident teenager said he and Roberts will only improve as Thorpe and Klim slog it out on the comeback trail for the London Olympics.
"A lot of press has been about us younger guys having to chase Thorpie and Kilmy - it's the other way around, they're going to be chasing us," Magnussen said.
"At the age we're at now we're improving markedly each year. I can't see any reason why we won't improve on that again next year."
Magnussen truly arrived on Tuesday night when he swam the fastest 100m in the world this year in 48.29sec - faster than Thorpe ever has over the distance. Thorpe wants in on the 100m but his best time is 48.56. No doubt competition will be tough to make the team.
Along with Magnussen, Australians Matt Targett (48.66) Matt Abood (48.69) and Roberts (48.79) are also ranked in this year's top 10 fastest men.
Magnussen believes he could get his time down to 47.5 to be in the chase for Olympic gold.
"I don't want go to London just as a participant," he said. I think 47.5 is achievable for me. I just like to be in the mix come London.
"If I can get down to 47.9 mark come worlds I'd be pretty happy."
Klim broke the then world record at the Sydney Olympics in 48.18 seconds.
The fire in Magnussen has been brewing for year. While he'd been part the gold medal winning relay team at the Commonwealth Games - it was languishing in the stands watching the men individually compete in the 100m that motivated him.
"I felt I was good if not better than them and could be getting better results," Magnussen said. "I have made it my personal goal to get an individual swim and obviously I really wanted to win this race and I have been thinking about it for a long time. It's possibly why the celebration was a bit over the top."
Magnussen flexed his muscles and did the "double gun pump" in celebration of his first national title.
"If we can get an international [win] in there will be an out of the pool celebration. A mixture of post-try celebrations in the NRL and wrestling moves."
"I won't hold anything back if I win that one."
Magnussen grew up in Port Macquarie and attributes his laid-back nature before races to growing up in the coastal town.
He's says he is in his "own little world." untill he steps on the block.
"My biggest assets in terms of an event like this is my composure," Magnussen said.
"I tried to relax and be Port Macquarie James Magnussen not 100m freestyeler James Magnussen, I tried to be really laid back and not think about it."
Magnussen said he was looking forward to getting home to Port Macquarie.
"They love it [swimming] back in Port Macquarie," Magnussen said. "I am looking forward to getting back to Port Macquaire and seeing a few people, go and see a few ex-teachers that didn't think I had it."
extract from -the daily telegraph