Andy Murray will have an operation on his back on Saturday -- nine days before the start of Wimbledon -- after being forced to pull out of Queen's earlier this week. The 37-year-old Scot, aiming to make a farewell appearance at the All England Club, where he is a two-time champion, has not been ruled out of the grass court Grand Slam, which starts on July 1. Murray managed just five games before a back injury forced him to withdraw from his second-round match against Australia's Jordan Thompson at the Queen's warm-up event in London on Wednesday.