rory mcilroy is favourite to win the 79th masters at augusta national .
bubba watson is the defending champion and chasing a third masters win .
tiger woods returns to action but has no form and worries over his game .
jason day and other big-hitters look set for strong week at masters 2015 .
course guide : mcilroy and more stars take you round augusta national .
click here for the masters 2015 leaderboard .