Injury concern for Shaun Marsh

Shaun Marsh joined the list of Australia's walking wounded at training in Melbourne on Wednesday. As Shane Watson returned to the crease after being struck on the helmet on Tuesday, David Warner tested out his sore thumb for the first time, and Ryan Harris continued to bowl in his recovery from a quadriceps injury, Marsh was struck on the left hand while facing Josh Hazlewood.

He immediately removed his glove and was checked by team doctor Peter Brukner, before heading indoors for further assessment. Marsh returned to the nets at the MCG later in Australia's training session and faced throw-downs from batting coach Michael di Venuto, but it was still another injury worry for Australia only two days before the Boxing Day Test.

Watson was hit on the helmet by a James Pattinson bouncer during Tuesday's training session and on Wednesday, he started tentatively by facing a bowling machine in the MCG's indoor nets, before heading outside to face net bowlers - not Australia's Test fast men. Warner said it was understandable that Watson was shaken by the blow to the head, given the recent death of Phillip Hughes.

"He's a little bit shaken up yesterday and better for it today," Warner said. "He went out there today and practised as well as I've seen him hit the ball. So it's one of those things that us batsmen, we always go in there not expecting to be hit on the helmet and it probably shook him up a lot more than he would have anticipated.

"And he was close to Hughesy and he was one of those guys that was on the field as well, so it brought back a bit of a memory for him and he got back on the horse and trained again today which was fantastic."

It was also an important net session for Warner, who was hit on the left thumb during Australia's second innings at the Gabba and had not batted at training since then. Warner began by facing throw-downs from di Venuto and was often pulling his left hand off the bat handle as he played his shots, but he warmed into the session and was later slogging the net bowlers around.

"It was okay, it was a bit sore when it hit the splice or the toe of the bat; that's to be expected, but I feel good and I'm ready to go," Warner said. "I tried to have a dip at the spinners to see if I could actually hit the ball as hard as I can, and it did feel real sore but I had to try and grind it out and get through that pain and I was able to do that."

Warner said he would field at mid-off rather than his usual position of gully in an effort to protect his thumb. He is far from the only Australian entering the match with an injury concern. Harris missed the Gabba Test due to a quadriceps strain but is expected to play at the MCG after bowling well in the nets over the past two days.

Harris is likely to replace Mitchell Starc, who was also bowling in the nets on Wednesday after hobbling away from training on Tuesday when he was hit on the knee while batting. Allrounder Mitchell Marsh batted in the nets on Wednesday as he continues to travel with the team, although he is not officially part of the squad for Boxing Day due to his hamstring injury.