Michael Campbell has been forced to withdraw from this week&aposs Sportsbet Australian Masters due to a persistent shoulder injury. The New Zealander has carried the injury throughout the second half of the year and was seen clutching at his right shoulder during last week&aposs Hong Kong Open. Doctors told the 2005 US Open winner that he would require an MRI scan before being cleared to play again. Campbell will undergo the MRI in Sydney on Friday. “I am really disappointed to have to withdraw from the 2008 Sportsbet Australian Masters,” Campbell said. “I have been carrying a niggling shoulder injury since The Open Championship in July and this flared up last week in Hong Kong.” In Campbell&aposs absence, caddie Michael Waite will carry the bag of fellow New Zealander Danny Lee, who is playing as an amateur this week. Lee, the world&aposs No.1-ranked amateur, has recorded victories in the top-ranked US and Western Amateur tournaments along with a top-20 finish in the PGA Tour&aposs Wyndham Championship. “Given my keen interest in helping New Zealand&aposs future stars, I have organised for my caddie, Michael Waite, to work for Danny Lee this week and hope his experience can assist Danny,” Campbell added.