MELBOURNE, April 23 (Reuters) - Everton midfielder Tim Cahill has returned to his native Australia for surgery on a persistent foot problem. The 28-year-old has already been ruled out of Australia's four World Cup qualifiers in June and is having surgery to ensure he is ready for next season's English Premier League. 'I hope to be back for pre-season ready for the first game of Everton's next season,' Cahill told Fox Sports after he arrived at Sydney airport. 'I'm just going to work hard... and nothing's going to stop me coming back.' Cahill missed the start of the season last year after breaking a bone in his foot in a pre-season game. He broke his foot again in March and was ruled out for the remainder of this season. He scored 10 goals in all competitions for Everton, who are fifth in the league and until recently were in the hunt for fourth place and a Champions League berth. They now trail city rivals Liverpool by eight points with three games remaining.