VADODARA, DEC 5: Nayan Mongia will leave for Australia tomorrow to replace injured wicket-keeper MSK Prasad for the remainder of the series. Board of Control for Cricket in India (BCCI) general secretary JY Lele said today that Mongia's departure will be decided tomorrow after the confirmation of available flights to Australia.Coach Kapil Dev said Prasad had fluid on his right knee and had only a 50-50 chance of playing the first Test. Prasad hurt his knee when he bumped it on a suitcase at Kuala Lumpur airport en route to Australia.``The doctor took fluid out of his troublesome knee and thought it would improve but it hasn't. He's going to have an MRI scan and we're just keeping our fingers crossed but we want to have a wicketkeeper here for the first Test,'' Kapil said.