When President Obregón was assassinated by pro-clergy forces sixteen days after his 1928 re-election, many generals and other important figures in Mexican politics urged Amaro to run for the office. He always politely declined, stating that he had "never thought to dedicate activities to politics." In February 1929, Amaro was injured during a game of fronton. He took a leave of absence from the Secretariat to seek medical attention at the Mayo Clinic in Rochester, Minnesota. During his three-month convalescence, which left him with a glass eye, Calles assumed the Secretariat, in which capacity he put down the Escobar rebellion against Emilio Portes Gil, who had been appointed interim president in the wake of Obregon's assassination.