Blackcaps v Australia: Justin Langer dismisses injury doubts over Dave Warner

Justin Langer has declared David Warner a certain starter on Boxing Day after the in-form batsman sent an injury scare through the Australia camp.

Warner, who was struck on the thumb during Monday's nets session, completed training with strapping around the thumb on Tuesday ahead of the second test against New Zealand at the MCG.

"He's fine," Australia coach Langer insisted.

"There was a little concern for about two seconds and then he saw the doctor and he's hitting balls again.

"We know how well he's playing at the moment, we know how much all the boys love playing test cricket and Boxing Day cricket ... so he'll be ready to go."

On Tuesday, Warner faced about 45 minutes of throw-downs from batting coach Graeme Hick and spin bowling coach Sridharan Sriram.

But he appeared to take his left hand off the bat quickly at times after striking the ball and did not face a bowler during the nets session.

"It's not unusual for Davey to do that," Langer said.

"He's in really good nick, he's a very experienced player now, he knows how to prepare.

"As I said, I've got absolutely no worries that he'll be raring to go."

AAP