Steve Smith admits he was rattled by the sight of a net bowler copping a blow to the head, one year after Phillip Hughes was felled at the SCG.

Australia's training session under lights on Wednesday was temporarily halted after Mitchell Marsh whacked a delivery back at a youngster in the nets.

The spinner, who plays grade cricket in Adelaide, did not have time to shield his face.

He did not hit the deck but it was a patently painful knock.

The tweaker avoided serious injury and was treated for a cut on the ear by team doctor Peter Brukner.

"I was a little bit shaken up to be perfectly honest with you," Smith said.

"I think a couple of the guys were as well.

"It was one year - to the day - since that horrible accident happened so I think it shook up a few of the players."

Marsh, David Warner and Steve O'Keefe were among the worried players nearby that came rushing over to check on the net bowler's condition after he was struck.

Shaken up ... Australian captain Steve Smith. ( AAP: Dave Hunt )

"Mitch Marsh certainly hit that ball pretty hard," Smith said.

"I think Mitchy is going okay, yeah.

"Luckily the guy was okay. I think he got a couple of stitches in the back of his ear."

It was the latest visceral reminder of how much the sport has changed since Hughes's death.

Smith admitted the day-night Test, which starts on Friday at Adelaide Oval, would be a confronting time for everyone that was close to Hughes.

Hughes lost consciousness when struck on the neck by a rising delivery from Sean Abbott during a Sheffield Shield match on November 25 last year.

One year on ... Phillip Hughes. ( Getty Images: Ryan Pierse )

He died two days later. The anniversary will be on day one of the third trans-Tasman Test.

"It was a pretty difficult time for us all coming here last year just after the horrible incident happened," Smith said.

"A year on we still have Hughsey at the back of our minds every time we walk out onto the field.

"We're going to be doing our best to play with a smile on our face and hopefully play well for Hughsey.

"Obviously it's a tough time for his family and his friends and we respect that and hopefully we can have a good week for Phillip."

AAP