|South Africa v England, fourth Test|
|Venue: Centurion. Dates: 22-26 January, day one play scheduled to start at 08:00 GMT|
|Coverage: Ball-by-ball Test Match Special commentary on BBC Radio 5 live sports extra, Radio 4 LW, online, tablets, mobiles and BBC Sport app. Live text commentary on the BBC Sport website.|
Captain Alastair Cook has challenged his England players to "guarantee" their places by performing well in the final Test against South Africa.
Cook's team hold an unassailable 2-0 lead in the four-match series but does not want standards to drop.
"This side has a long way to go and there's a huge amount for the guys to play for personally," he said.
"As long as our attitude is right and people focus on what they can do to help the side, then we should be OK."
Nick Compton, James Taylor and Alex Hales have only played in 12, six and three Tests respectively and Cook wants them to impress before a busy summer that includes three Tests against Sri Lanka and four versus Pakistan.
In an interview with BBC Radio 5 live, Cook added: "Alex Hales got a good 60 in Cape Town and will be desperate to make his mark, as will some others, so they are guaranteed picks for the first Test against Sri Lanka at Headingley.
"Hopefully they can go out and show the world how good they are. What a great stage to do that when you're 2-0 up in the series.
"It has been a really good tour, we haven't lost, and we've played some really good cricket. Winning in South Africa is another stepping stone but it is not the end of the road for the guys."
Cook needs 117 more runs to become the first Englishman to score 10,000 in Tests.
Fighting talk from South Africa
Despite losing the series, South Africa captain AB de Villiers expects his side to capitalise on England's "weaknesses".
"Their bowling is experienced but some of the guys have lost some pace over the years," said De Villiers.
"The batting is not 100% best-in-the-world material, there are areas we can expose if we start well with the ball. We can find cracks. They are not unbeatable.
"England seem to know what they are doing, they understand their roles really well, but there's also no doubt there are weaknesses there."
England, who are without the injured Steven Finn (side strain), will choose between Chris Woakes, Mark Footitt and Chris Jordan on Friday morning.
"It is quite a big decision to make. All three are different options and all three are desperate for it to be them who gets selected," said Cook.
"When you're weighing up a lot of options you can overcomplicate it, so I think it's just a case of playing our best side."
South Africa are set to include opening batsman Stephen Cook, while seamer Kyle Abbott and off-spinner Dane Piedt could return to the side.
BBC Radio 5 live's cricket correspondent Jonathan Agnew:
"Before the final match in the last Ashes, with England in an unassailable position, Alastair Cook phoned every member of the team and urged the need to stay focused. It did not work and England were thumped, so the challenge here is to ensure that does not happen again.
"There are people like Hales, Compton, Taylor and Finn's replacement, whoever that might be, and for them this match is crucial for their futures. But even established players like Cook himself and Anderson need to stamp their mark on this series.
"There is grass on the pitch and further changes to an unsettled South Africa team, possibly including a debut for 33-year-old Stephen Cook, the son of former opening batsman Jimmy Cook."