Ben Stokes took his place in England's Boxing Day Test against South Africa, despite his father Ged remaining in a stable but serious condition in hospital.
Stokes senior was admitted to intensive care in Johnnesburg after being taken ill on Monday night but he has responded well enough to treatment for England's vice-captain to start the match in Centurion.
England captain Joe Root said: "It's very tough on Ben and he's going to play this game. I know his family are very proud of him for that."
The tourists were not able to name their preferred XI, though, having lost Ollie Pope, Chris Woakes and Jack Leach to the sickness bug which has swept the camp.
Pope would have batted at No 6 had he been fit to play but his absence opened the door for Jonny Bairstow to return to the side.
Woakes may also have played but with the Warwickshire man quarantined at the team hotel, all-rounder Sam Curran took the field.
But seamers Jofra Archer and Stuart Broad recovered sufficiently from flu to take their place in the side in what is an all-seam attack.
Root won the toss and opted to bowl first, perhaps persuaded by a light covering of live grass.
James Anderson was presented with his 150th cap by his former captain Nasser Hussain – the ninth player to reach the landmark in Test cricket, the second Englishman after Alastair Cook and the first specialist fast bowler.
"For James Anderson to play 150 Tests shows a huge amount of ability," Root said. "It's a testament to his fitness and desire."
South Africa have handed debuts to middle-order batsman Rassie van der Dussen and all-rounder Dwaine Pretorius.
Aiden Markram has recovered sufficiently from a hand injury to open the batting, while No 3 Zubayr Hamza and fast bowler Anrich Nortje have just two test appearances each in what is a new-look line-up.
Proteas captain Faf du Plessis said: "We would have batted first anyway. Generally the pitch on Day 1 is slow, Day 2 and 3 is decent and after that it goes up and down.
"The first two Tests are our best supported grounds. We play well here. That means absolutely nothing here – this is a new team."
