Andy Murray’s bid for a third straight Olympic singles gold medal ended before it began when he withdrew ahead of his first match with a minor thigh strain. The Scot had been due to take on ninth seed Felix Auger-Aliassime of Canada on Sunday but was replaced on the order of play by Australian Max Purcell. Murray had been upbeat about his prospects after an excellent doubles victory with Joe Salisbury on Saturday but experienced tightness in his quad muscle and was advised not to try to compete in both events.