Nationals catcher Wilson Ramos has a torn anterior cruciate ligament in his right knee, the latest major setback for the NL East leaders. Ramos\' knee buckled as he chased a passed ball during the seventh inning of a 2-1 win over the Cincinnati Reds on Saturday night. He fell on his back in pain and had to be helped off the field, putting little weight on the knee. An MRI confirmed that he tore the ligament, costing the Nationals their young catcher. He\'s the 11th Nationals player to go on the disabled list this season. The Nationals called up catcher Sandy Leon from Double-A Harrisburg to back up Jesus Flores. The 23-year-old Leon was batting .319 with a homer and 12 RBIs in 27 games at Harrisburg.