Eamon Sullivan's suffered a fractured heel during a recent training camp in Mexico. The Olympic 100m freestyle silver medallist had raced twice at the Summer Series heritage meet in Sydney today before he heard the bad news in a message left on his mobile phone.

Sullivan told reporters at the meet that he would not know until examining an MRI this weekend how long he was likely to be sidelined, though he expected to be on top form at world championship trials in April.

"With an X-ray to show up a fracture, you have to get the right angle and the x-ray (in Mexico) didn't show it, so we just assumed it was bruising," Sullivan told reporters. "We trained throughout the whole three weeks with a lot of pain and still coming in today I knew it was going to hurt racing and even just walking around. But I just happened to check my phone after my first two races and I had a text from my physio and my doctor. I had an MRI yesterday just to make sure everything was OK and they found out there was a fracture."

This marks the third successive January in which Sullivan has been plagued by injury, hip operations part of past woes. He told reporters that he believes his latest injury was sustained on the second day of the NSW Institute of Sport camp in San Luis Potosi in Mexico. Initial x-rays in Mexico had not revealed the fracture, according to an AAP report.

On the equivalent of 'heats' day at the meet in Sydney, with the points showdown due tomorrow, a celebrity 4x100m free relay revealed something of the form of former high-flyers of the race pool. The splits of the famous included: 58.48 for Michael Klim, 1:01.69 for Susie O'Neill, 1:07.77 for Linley Frame (but she was a breaststroke ace after all ...), and 59..44 for backstroke ace Matt Welsh. In her first official race in the big race pool over 100m freestyle (more to come tomorrow), comeback sprinter Libby Trickett clocked 59.31 - at a cruise we take it.