Former South Africa captain Joost van der Westhuizen is in a "critical condition" in hospital as he continues to fight motor neurone disease.
"The family and friends of Joost ask that you all pray for Joost," read a statement on his J9 Foundation website.
"When we have updates, we will let you know. For now, we ask that we all bow our heads in prayer."
After being diagnosed, Van der Westhuizen set up the J9 Foundation, which provides support and care to people with motor neurone disease.
Van der Westhuizen is regarded as one of the finest scrum-halves in rugby history and won 89 caps for the Springboks between 1993 and 2003, scoring 38 tries.
He played in his first of three World Cups in 1995 when the Springboks beat New Zealand in the final, and won the Tri-Nations Championship in 1998.