Can Hackett still hack it at 34?

Australian swimming great Grant Hackett has confirmed his comeback to the pool after six years and has entered next April's national trials, local media reported on Saturday.

Hackett, who won 1,500m freestyle gold at the 2000 Sydney Olympics and defended the title four years later at Athens, sparked speculation of a return months ago after being spotted training on the Gold Coast with his old coach, Denis Cotterell.

Rated one of the greatest distance swimmers ever, 34-year-old Hackett has endured a torrid year, and flew to the US in February to spend time in rehab to treat a dependency to Stilnox, a sleeping medication.