The Washington Nationals placed catcher Wilson Ramos on the 15-day disabled list Sunday with a torn anterior cruciate ligament in his right knee.
Ramos suffered the injury during Saturday's 2-1 win over the Reds.
The injury occurred as Ramos was tracking down a passed ball from Jordan Zimmermann. Ramos hurried to the ball, but as he went to pick it up, his knee buckled underneath him.
Ramos remained on the ground while wincing in obvious pain for several minutes before being carried off the field.
Ramos was hitting .265 with three home runs and 10 RBI in 25 games this season.
Washington selected the contract of catcher Sandy Leon from Double-A Harrisburg to fill the roster spot.
Leon batted .319 with 10 doubles, one home run and 12 RBI in 27 games this season with the Senators.