WASHINGTON, June 14 (Reuters) - President Donald Trump has four leading candidates under consideration to replace outgoing White House press secretary Sarah Sanders, a Trump confidant said on Friday. The four are deputy White House press secretary Hogan Gidley, Stephanie Grisham, who is first lady Melania Trump's communications director, former State Department spokeswoman Heather Nauert and outgoing Treasury Department spokesman Tony Sayegh, the source said on condition of anonymity.