Last week's terrorist attacks in Mumbai had forced England to abandon the last two matches of the One-day series and return home.
Several of the team's leading players, including Andrew Flintoff and Stephen Harmison, are unwilling to return for the two-match Test series even if security expert Reg Dickason's report terms India to be safe.
"The players will be left to make their own decisions and they won't be forced to go back even if the security reports are favourable. If we do go back we've got two tough Tests to play so the focus has got to be right. Players need to be on full mettle," Miller told 'The Independent'.
"There is no point in players going out there if their mind is on self-preservation. We need them performing with bat and ball. But, depending on the character involved, it might not be right for some.
"If some players choose to stay at home the selectors will have to re-assess, but their decision to miss the Test series will not count against them. As cricketers we owe it to the game to complete those fixtures but the security of the players is paramount," he added.
Miller said, although, there is no specific time-period for the players to decide, he is expecting to take a call at the earliest.
"I've not spoken to everyone yet but Kev (Pietersen) is doing a ring round to canvas opinion. I'm expecting to hear back from everyone over the next day or so. There is no time-line but players realise that we have to move fast if we are to go back," he said.
