Sydney: Australia skipper Michael Clarke has been ruled out of his side's one-day match against Sri Lanka in Sydney on Friday due a hamstring injury, which he suffered against India in Adelaide on Sunday in the fourth match of the ongoing tri-series. "I have a grade one hamstring strain so will be out of Friday's game vs SL but hopefully be back for Sun against India in Bris. Good news," Clarke tweeted.The 30-year-old hurt himself while fielding during the four-wicket loss to India, and underwent scans on Monday that confirmed the low grade nature of the injury.Australia team physiotherapist Alex Kountouris said Clarke's availability for their next match - again against India on Sunday in Brisbane - will be determined later this week. "Michael Clarke sustained a low grade right hamstring strain in the ODI versus in India in Adelaide on Sunday," said Kountouris. "He will not recover in time to play in Australiaâs next Commonwealth Bank Series game on Friday in Sydney against Sri Lanka, but I will assess him later this week and decide on his availability for the game in Brisbane on Sunday, 19 February, against India."Reports suggest Ricky Ponting might be asked to captain the side in Clarke's absence, with David Warner set to continue in his role as vice-captain. Wicketkeeper and Test vice-captain Brad Haddin may also be in the frame, if he returns to the squad after being left out for the first three matches. Regular vice-captain Shane Watson only returned to club cricket last weekend after a six-week absence with a calf injury. The Cricket Australia National Selection Panel will now name the squad for the next block of tri-series matches on Tuesday, instead of on Monday, as had been originally planned. "An acting captain will also be confirmed on Tuesday," the CA said.Selectors face several decisions in choosing their next one-day squad, with Clarke's injury and wicketkeeper Brad Haddin's future key discussion points. Haddin missed Australia's initial three matches of the tri-series, with selectors saying he was rested as Matthew Wade took his spot.Australia's batting line-up also faces scrutiny, with newcomer Peter Forrest making 66 on debut in Sunday's defeat by India to bolster his chances of remaining in the squad."I know the selectors are meeting today so I'll be sitting by my phone tomorrow (Tuesday) hoping to get a call," Forrest told reporters in Brisbane on Monday."Yesterday was a great day and one I'm not going to forget. It was nice to contribute but it would have been a lot nicer had I got 80 plus or a hundred and got the side to a win."Australia are currently top of the tri-series table with two wins and a loss, but could move down to second if India beat Sri Lanka in Adelaide on Tuesday.