Assistant coach Graham Thorpe revealed his doubts over the fitness of Ben Stokes, Jonny Bairstow and Jos Buttler ahead of the Test finale.
As things stand, Stokes is waiting for the results of a scan on a side problem. Meanwhile, Buttler and Bairstow could be forced out with fractures.
The news comes at the worst possible time for England who are 358 runs adrift going into the final day of the fourth Ashes Test.
Sam Billings has already been added to the squad as wicketkeeping cover for Buttler and Bairstow, with Saturday's emergency stand-in Ollie Pope and Dan Lawrence also waiting in the wings.
Assistant coach Thorpe, who is in temporary charge while Chris Silverwood completes his Covid-19 isolation, said: "We've obviously got some blows. It's possible (they will miss the final Test) but we will be assessing all of that.
"Obviously, Sam has been called into the group and that's obviously a good indicator of some of the concerns we have with the injuries.
"But I am sure the lads will take whatever they need to take to get themselves in a position where they are capable of performing on the final day. They will all bat and they will all do their very best, I know that.
"At the end of the game we have to assess who is potentially going to be available. With Stokes, his injury is not a great one being an all rounder."
Pope impressed as he stepped up from the sidelines to take up the gloves. It may be a role he has only performed half-a-dozen times in first-class cricket but the 24-year-old put on a solid display.
"I thought Ollie did fantastically well, it's a bit like a goalkeeper… if you don't really notice them that means that they've done very well," said Thorpe.
"It took me a while to realise it was him back out there. That gives us options."