Millers to take on Warnock's Cardiff
Ticket details have yet to be confirmed. A further announcement on sale dates and prices will be made in due course.
It is one of several friendlies confirmed for the Millers, with the current list being:
Saturday 7th July (A) Parkgate FC 1pm
Tuesday 17th July (A) Sheffield FC 7.30pm
Tuesday 17th July (A) Stocksbridge Park Steels 7.30pm
Wednesday 25th July (H) Cardiff City 7.45pm
Saturday 28th July (A) Mansfield Town 3pm