The tourists trail the hosts by 369 runs with two days of play remaining, and the 27-year-old picked up the foot injury in his first innings total of five while facing Australia's leading wicket-taker in the series, Mitchell Johnson.
"Something showed up on the X-ray that was a little bit inconclusive, so I had to go to an MRI and they have been sent back to the UK to have a look at," he told The Mirror.
"The treatment at the minute is a lot of ice, elevation, keep off it, because I want to play a part in this series. It won't be Monday, but hopefully in future.
"I will put my hand up to bat if it improves a little bit overnight and we need that, but I won't be bowling."
England are on course to lose The Ashes series for the first time since 2007.