England must "earn the right" to start thinking about T20 World Cup permutations, says Jos Buttler, whose side face a humiliating early exit in the group stage.

Matthew Mott's white-ball  were defeated by Australia on Saturday, with their 36-run loss leaving them staring at a group-stage elimination in their T20I title defence.

That result was compounded by Scotland's thrashing of Oman with 41 balls to spare as England suffered another blow to their hopes of progressing via net run-rate.

Another must-win match against Oman looms on Thursday, where England have to triumph before any other calculations of permutations can begin, says captain Buttler.

"I don't think it's s**t or bust quite yet," Buttler told reporters in Antigua. "I think it's quite clear what we need to do and how we need to play.

"First and foremost, we need to win the game against Oman to have any chance going forward into the next one.

"So we have to earn the right to try and win the game. And if we can get ourselves in a position to affect our net run-rate, obviously that's what we need to do."

England then face Namibia on Saturday to round off their group-stage campaign, though two victories for Buttler's side may still not be enough.

Scotland could still knock them out by beating Australia in their final match after England meet Namibia, when the Scots will have an advantage of a clear picture of what is required.

"We've looked at a few little bits but it's going to be ever-changing throughout the game," Buttler added.

"I don't think we need to consume too much energy today and tomorrow saying 'we need to score 'X' amount of runs or win by this much'. I think those kinds of things will develop on the day.

"That's the situation we find ourselves in, so we have to be aware of that, but not be consumed by that.

"If we try and do that bit first and forget about trying to win the game and lose, then you've got no chance anyway.

"So I'd rather have some kind of chance going into the last game, and know exactly what we need to."

England's white-ball struggles at the tournament have raised questions about Buttler's captaincy and coach Mott's tenure.

Buttler has no interest in the speculation surrounding his stewardship, however.

"I care more about the team than the media and the outside noise," he added. "That's always there, it's part of international sport. If you get to this level, you have to be able to deal with it, the job you guys do, that's the job TV does.

"It's probably harder to completely ignore it in this day and age, but there's a level of acceptance. Our focus has to be on what we can do with our performance.

"I've played the game long enough now to know that it's very good at building people up and pretty good at criticising when it doesn't go right, especially in England.

"I do the same thing when I'm watching a game of football or rugby – 'how's he missed that from there?' 'How did he miss from one-yard out', or 'someone's dropped the ball over the line'. Simple things like that.

"People care. That's why we're able to do what we do because people care and they want to watch. We're a proud team, we want to perform really well for all the fans.

"But to be honest, all the focus is on us and how well we can play. If we play as well as we can, we'll make our fans happy."