QUEENSLAND batsman Usman Khawaja has been placed on standby for Australian captain Michael Clarke for the Boxing Day Test.
And paceman Jackson Bird has been called into the squad to replace fellow injured Tasmanian quick Ben Hilfenhaus.
Bird looms as a likely 12th man with Mitchell Johnson almost certain to step into the starting XI after missing out in Hobart.
Speaking after Australia bowled out Sri Lanka on the last day of the first Test, Clarke said it was too early to know how his injured hamstring would respond to treatment.
"It's a strain ... to what level I don't know," Clarke said.
"I've got seven or eight days leading up to the Boxing Day Test. I'm really confident I'll give myself every opportunity to be right."
The skipper said he had not seen much of Khawaja's recent efforts at the domestic level, but said his performances at Sheffield Shield level warranted him being next in line.
He used a similar argument to justify Bird's inclusion.
"At the end of the day if you're putting good numbers on the board you put yourself in line to play for Australia," Clarke said.
"Jackson is the leading wicket taker in first class cricket this year. That was the main reason for including him in the squad."
Clarke wasn't prepared to buy into the allegations of ball tampering levelled against man-of-the-match Peter Siddle, raised after televison footage raised questions about whether the fast bowler was using his thumbnail to potentially rough up one side of the ball.
"We play in the spirit of the game. We play very hard on the field ... I don't believe we cross the line," Clarke said.
Siddle also laughed off the suggestion, while Sri Lankan captain Mahela Jayawardene said he was happy to move on if match officials found no isue.
Late yesterday the ICC issued a statement saying the matter had been investigated and there was no evidence to suggest the condition of the ball had been changed.
Jayawardene also said he was pleased with the way his players fought out the mathc in difficult conditions against "a very good team", but added improvement was needed in a couple of key areas.
"We were not consistent with our bowling in certain situations, and we need to put more runs on the board in the first innings," he said.
The skipper singled out Siddle as the player who changed the course of the game on the final day, taking two crucial wickets just after tea.
"At tea it was pretty much even. We had 30-35 overs to bat and two batsmen 'in', but we lost two wickets in the space of six or seven overs," Jayawardena said.
Australian squad for Boxing Day Test
- Michael Clarke (c)
- Shane Watson (v-c)
- Ed Cowan
- David Warner
- Mike Hussey
- Mitchell Starc
- Jackson Bird
- Usman Khawaja
- Nathan Lyon
- Peter Siddle
- Matthew Wade
- Mitchell Johnson
- Phillip Hughes