It comes after months of preliminary hearings over the case, which centres around Ms Rooney publicly accusing the fellow footballer’s wife of being the source of stories about her that were leaked to The Sun newspaper.
The wife of ex-England star Wayne Rooney was dubbed “Wagatha Christie” when she made the allegations, which she claimed had followed a months-long “sting operation”.
She wrote: “It’s ………. Rebekah Vardy’s account.”
Mrs Vardy, who is married to Leicester City striker Jamie Vardy, denies the accusations and is suing Mrs Rooney for libel.
Under English defamation law, the onus is now on Mrs Rooney to prove her post was “substantially true”.
The trial is expected to begin at London’s Royal Courts of Justice on Tuesday following the preliminary hearings, which neither of the pair attended.