Castleford Tigers head coach Ian Millward has been granted compassionate leave following the death of his 19-year-old son.
Robbie Millward was taken in ill at home on Sunday and was rushed to Bolton Hospital where he died later that evening.
In a statement, the Millward family has thanked well-wishers for their support.
"On behalf of all our family, we would like to thank everybody for their kind messages of support, especially the Rugby League family from both the UK and Australia," read the statement.
"The messages have been of comfort in this time of great sadness. Robbie was a healthy young boy who died from a condition called sudden adult death syndrome, which comprises of a massive heart attack; the sudden nature of his death is making it even harder for us to deal with.
"We ask that journalists allow us the space and time needed to come to terms with the loss of Robbie. Instead of flowers, we ask any well-wishers to donate to the British Heart Foundation."
Millward took over Castleford earlier this year.
