Ollie Pope is set to have scans within the next 24 hours on an injured shoulder that suffered blows on multiple days of the Lord's Test match last week.
Pope stepped to the crease in both innings of the match but appeared visibly hampered by the injury in the outfield, leaving him in doubt for the next test in just three days' time.
Intriguingly, England decided to release two of their backup options in Matthew Potts and Rehan Ahmed from the squad, leaving Dan Lawrence, who bats for Essex at an average of 44.6, as the lone replacement if Pope is ruled out officially.
Moeen Ali sits as a possible replacement as a specialist spinner with some all-rounder tendencies, with reports suggesting that he is fit and firing for a return from his finger injury.
Mark Wood is the last name to feature in a potential squad change, given the declining form of James Anderson and the one-paced nature of the England bowling attack. Wood ruled himself out of Lord's to allow his body the extra rest required to perform at 100%; if he is not the desired replacement for a potential Anderson commission, then Chris Woakes may be.
For Australia, it appears Todd Murphy will be the natural replacement for Nathan Lyon after his performance in India, leaving Head, Smith and Labuschagne as handy secondary spin options.
The only other selection query for Australia revolves around Scott Boland, who is the clear backup option if Hazlewood is omitted or managed.
Hazlewood took three crucial poles to help Australia get to 2-0 in the series but he was noticeably targetted by Ben Stokes in the final innings at Lord's and often looked under duress in the outfield and while bowling.
Either option comes with a risk factor given the uncertainty of the Headingley pitch; a dead pitch will hurt Boland given his lack of bounce, while a live pitch could bring his seam ability into the action.
With just one win required for Australia to retain the Ashes, selectors of both sides will be feeling the heat of this historic series, with England in particular under pressure to perform with their best side possible.
Tune into the third test of the Ashes this Thursday, 8:00pm AEST for a rematch of 2019's legendary match at Headingley.
