|South Africa v England, 1st Twenty20|
|Venue: Cape Town Date: 27 November Time: 16:00 GMT|
|Coverage: Live text commentary on the BBC Sport website and updates on BBC Radio.|
England do not know their best Twenty20 side with less than a year until the World Cup, says captain Eoin Morgan.
They start a three-game series in South Africa on Friday, and potentially have a further 14 games before the tournament in India.
"There are probably seven or eight guys who are pretty strong candidates to be in our strongest XI," said Morgan.
"Winning this series would be great, but it is more important we get players roles right and they feel comfortable."
The T20 World Cup, due to start in Australia last month, was postponed by a year because of the coronavirus pandemic.
England are second in the International Cricket Council T20 rankings and a 3-0 series win in South Africa would take them level on points with leaders Australia.
South Africa are ranked fifth, having last won a T20 series in March 2019.
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Who will open the batting for England?
Wicketkeeper Jos Buttler is set to open alongside Jason Roy, despite all-rounder Ben Stokes averaging 40.71 at the top of the order for Rajasthan Royals in the Indian Premier League (IPL) that finished this month.
"Jos is one of our greatest-ever white-ball cricketers. He probably is the best but he's only halfway through his career," Morgan told the Tuffers & Vaughan podcast.
Where Stokes, Morgan, Jonny Bairstow and Dawid Malan, the top-ranked T20 batsman in the world, bat is still to be decided.
"We have a group of players that both are very good at batting in the top three, but also want to bat in the top three," said Morgan.
"We need a really strong top seven to be able to win or compete at a World Cup."
South Africa captain Quinton de Kock said: "There are a lot of guys to watch out for - you can't pick just one guy. Any player in the England team, if they come off they can really hurt you."
Pace bowlers ready to shine
One of the areas where the series could be decided is how the fast bowlers perform.
England are likely to include Jofra Archer and Mark Wood in their side, while Chris Jordan - two short of Stuart Broad's England record of 65 T20 wickets - and Reece Topley are also part of a 15-man squad.
Archer won the MVP award at the IPL after taking 20 wickets at an average of 18.25.
South Africa, meanwhile, have Kagiso Rabada, who won the purple cap for the most wickets at the IPL with 30, and Anrich Nortje, who took 22 wickets and bowled the quickest delivery of the tournament.
When did the teams last play?
Friday's match in Cape Town will be England's first overseas since their tour of Sri Lanka was ended by the pandemic in March, although they completed their home international schedule behind closed doors this summer.
South Africa have not played since their one-day series against India was cut short in March.
Their preparations for this series - which will be played without fans and in a bio-secure bubble - have been disrupted by two positive Covid-19 tests, meaning their intra-squad games were cancelled.
Those two players are isolating, and the rest of the 23-man squad have tested negative in the past 48 hours.
Where are the games?
The first and last T20s are day-night matches (16:00 GMT) at Newlands in Cape Town, while the second game starts at 12:30 at Boland Park, Paarl.
The series will be followed by three one-day internationals from 4 December.
How can I follow the series?
There will be live text commentary on all the matches on the BBC Sport website.
Cricket correspondent Jonathan Agnew will provide updates on BBC Radio, with analysis from England bowler Tymal Mills, former England captains Alastair Cook and Michael Vaughan and ex-England women's batter Ebony Rainford-Brent.
There will also be regular Test Match Special podcasts after the games.