World 100m freestyle swimming champion James Magnussen believes his sizzling early-year form is ringing alarm bells among his overseas rivals.

Magnussen 20, who burst onto the international scene last year with his sensational world title win, clocked a blistering 48.05 seconds to win the South Australian 100m title in Adelaide last month.

He will have his final hitout before next month’s national championships and Olympic trials at this week’s NSW titles in Sydney.

Asked if his he was sending his overseas opposition a message with his scintillating form in Adelaide, Magnussen told AAP “I think it would kind of have to.

“To be swimming those times without taper has got to send alarm bells.”

As for his expectations this week, Magnussen said “just to improve on that mark that I set in Adelaide would be a bonus.”

He hoped to go under 48 seconds in Sydney but said that wasn’t a specific goal.

Magnussen will contest the 50, 100 and 200m freestyle events.

Touted as Australia’s great swimming hope at the London Olympics, Magnussen isn’t fazed by the growing expectations generated by his success.

“I quite enjoy it, I don’t think it’s become a burden at all,” Magnussen said.

The Port Macquarie-bred speedster has won world, national, Queensland and South Australian 100m titles but has yet to claim the senior NSW championship over that distance.

“I was probably favoured to last year, but my house was broken into (on the day of the event),” said Magnussen, who withdrew from the final.

“It’s disappointing that the Queensland and South Australian titles have come before a NSW one, but to add that one to the tally would be nice.”

He was bullish about Australia’s Olympic relay prospects, after being part of the gold medal-winning 4x100m freestyle team at the world championships.

“I think we should be pretty strong favourites going into the Olympics with all the guys who were in the team last year still involved,” Magnussen said.

“This year with younger and older guys making a comeback we’re looking pretty good.”

One of the older guys is five-time Olympic gold medallist Ian Thorpe, whose comeback has yet to reach any great heights.

Magnussen warned against writing off Sydneysider Thorpe, who will not be swimming at the NSW titles.