Joe Root has been sent for scans after being struck in the abdomen during England's warm-up prior to day four of the second Ashes Test at Adelaide Oval.

The England skipper did not start the day's play on the field, after the blow not long prior to the scheduled commencement.

Root, who made 62 in the first innings, was hit in the abdomen while facing throwdowns in the nets.

"He is currently being assessed by the England medical team," an England team spokesman said in a statement.

Root did return to the playing field in the first session on day four but appeared sore.

Australia resumed on the fourth day at 45-1, with England taking three wickets in the opening 12 overs without Root on the field, with vice-captain Ben Stokes stepping in as skipper.