Rotherham say they are looking to arrange an alternative fixture, which we'll bring news on as we have it.
Here's the list of friendlies to take place at Don Valley, priced at £10 adults and £5 concessions:
Sat July 19: Derby County 3pm
Tues July 22: Scunthorpe Utd 7.30pm
Sat July 26: Barnsley 3pm
Sat Aug 2: Hartlepool 3pm
The same prices also apply for the away games at Stockbridge PS on Monday July 28th and at Sheffield FC a week earlier on Monday 21st.