It was bad enough for England to lose Alastair Cook and James Vince towards the end of the third day of this compelling opening Test but there were perhaps even greater implications for them in the condition of two other pivotal players.
There were concerns here about the fitness of Jimmy Anderson while another key man in Moeen Ali looked worryingly out of sorts with the ball as he struggled to make the impact of Australia's off-spinner Nathan Lyon.
England insisted there was nothing wrong with Anderson after he appeared to grimace while bowling towards the end of the first session of the third day when Australia were in trouble at 209 for seven.
James Anderson suffered an injury scare on day three of the opening Ashes Test in Brisbane
Anderson appeared to be in discomfort as he bowled towards the end of the first session
Yet the pressure on Australia was immediately eased when Anderson failed to resume the attack after lunch and the leader of England's attack was to bowl just four overs between lunch and tea in between spells off the field.
Even when England were struggling to finish Australia off Joe Root bowled himself at last man Lyon rather than turn to the man who could have been expected to rapidly mop up the tail.
The last thing England need is to have a problem with such a key bowler ahead of a second Test under lights in Adelaide starting on Saturday that perhaps gives them their best chance of victory in this Ashes series.
Moeen, such an important figure in this England side in the absence of Ben Stokes, missed the first two warm-up matches of this tour because of a side strain but looked to have recovered full fitness in Townsville.
Now he saw Lyon turn the ball from the first day on a pitch renowned for pace and become Australia's most effective bowler in England's first innings.
It put the emphasis on Moeen to repeat the