The Washington Nationals have placed catcher Wilson Ramos on the 15-day disabled list with a right hamstring injury and called up catcher Sandy Leon from Triple-A Syracuse.Washington Nationals catcher Wilson Ramos, right, tags out San Francisco Giants' Pablo Sandoval in the sixth inning of a baseball game Tuesday, June 10, 2014, in San Francisco. Sandoval was attempting to score on a hit by Giants' Brandon Crawford.