Australia star batsman Steve Smith is set to undergo a fresh concussion test before the second one-day international against England at Old Trafford on Sunday (13 September).
Smith missed Australia's 19-run win in the first of a three-match series against world champions England after being hit on the head by a throw-down from a member of the tourists' coaching staff while batting in the nets on Thursday.
An Australia spokesman said Smith was being rested as a precaution despite passing a concussion assessment and would have another such test on Saturday.
"Steve Smith got a knock on the head yesterday (Thursday) in practice so it's a precautionary measure to leave him out," Australia captain Aaron Finch told Sky Sports at Friday's toss. "(Marcus) Stoinis will bat at three."
Stoinis made a useful 43 as Australia, following a sticky start, compiled a total of 294-9 in their first match against England at this level since last year's World Cup semi-final defeat.
Fast bowler Josh Hazlewood and legspinner Adam Zampa then reduced England to 57-4.
Australia remained on top despite a maiden ODI hundred from Sam Billings, out for 118 off the last ball of the match as England finished on 275-9.
But on a chilly evening in this day/night clash, left-arm quick Australia's Mitchell Starc appeared to be struggling towards the end of a wicketlesss 10-over spell that cost just 47 runs.
The team spokesman said Starc had a "minor amount of soreness in the top of his leg/groin area" that ought to benefit from a day's rest on Saturday.
Smith was dramatically felled by a 92mph bouncer from England's Jofra Archer during last year's drawn second Test at Lord's.
Despite missing the third Test at Headingley, Smith still scored 774 runs, including three hundreds, at an average of over 110 during a five-match series that ended all square at 2-2.