Potchefstroom - England captain Alastair Cook said on Saturday he expected strong competition for places as his team prepares for a four-Test series against South Africa.
"We don't know our best XI quite yet," said Cook at the team's first press conference following their arrival in South Africa on Friday.
The team travelled directly to Potchefstroom, just over an hour's drive away, to prepare for their first match, a three-day encounter against a South African invitation side starting on Tuesday.
They will meet South Africa A in a second three-day game in Pietermaritzburg from December 20 before the first Test starts in Durban on December 26.
"There are a lot of things up for grabs," said Cook.
"There are players who can make a name for themselves. We're trying to find our best combination, people who can nail down their place in the side.
"There's a lot to play for internally so I expect our nets in the next few days will be fairly intense."
Coach Trevor Bayliss said England did not attach great significance to South Africa's 3-0 defeat in a Test series in India recently.
"I don't think that really matters," he said. "Everyone knows it's very hard to win away from home.
"We're playing the best team (in the world rankings) and they're playing at home. We're under no illusions that it's going to be difficult."
Bayliss said the two three-day matches would be an important guide to selection but dropped a strong hint that Alex Hales, who has previously only been capped in limited overs matches, was a front-runner to be Cook's opening batting partner.
"He has been with the squad for a while and deserves an opportunity to make that spot his own," said Bayliss.
That would leave Nick Compton and Gary Ballance to fight out the number three position.
"I've got an idea who should play but we've got two very important practice matches before the first Test which could go a long way to finalising that position."
Bayliss also said Jonny Bairstow was the leading contender to keep wicket in the Tests. "He's the incumbent and he hasn't done a lot wrong. I envisage he will be starting."