England spinner Jack Leach will make a premature return home from the tour of South Africa after struggling to recover from illness.
Leach contracted sepsis during the tour of New Zealand in November and was also struck down with gastroenteritis and flu before the first Test against the Proteas last month.
The left-arm tweaker has not been able to regain full fitness and the tourists announced ahead of the third Test in Port Elizabeth that he will head back to England immediately.
"It has been an unfortunate time for Jack with illness and since the Test series in New Zealand six weeks ago, he hasn't been able to get 100 per cent fit," said England head coach Chris Silverwood.
"This has hampered his preparation in South Africa and despite his best endeavours he is not in a position to make himself available for selection for the final two Test matches.
"He is a great lad to have around the squad and his infectious personality and popularity will be missed.
"However, his focus has to be getting himself better and receiving the optimum levels of recovery and treatment, which is best served back in England without any distractions.
"I have no doubt that he will return to full fitness in the medium-term and hopefully he will recover in time for our tour of Sri Lanka in March."
Mark Wood is reportedly set to get the nod ahead of fellow paceman Jofra Archer to replace the injured James Anderson on Thursday when England go in search of a 2-1 lead at St George's Park.