This is due to an electrical fault at the racecourse which means it is unable to stage racing.
The fixture at Newcastle will be an afternoon eight-race card with the ability to divide to nine races if required. The races will be as close as possible to those originally scheduled at Doncaster.
Entries will close tomorrow, Thursday 30 July at 12 noon with declarations at the 48-hour stage as normal. Race conditions, times and further fixture information will be available via the Racing Admin site www2.racingadmin.co.uk shortly.
Jon Pullin, Racing Director at Arena Racing Company, said: