Closer Jason Grilli was placed on the 15-day disabled list on Tuesday by the Pirates, with what for the time being is classified as a "right forearm strain."

Grilli departed early afternoon for Pittsburgh, where he will undergo further medical tests to determine the source of the pain that forced his ouster from Monday night's game with the Nationals.

"He'll be seen by our doctors, so we'll get a more thorough evaluation. The initial read was that he'll be down at last 10 days, so the DL became a no-brainer," said Pirates general manager Neal Huntington. "Until we get a more thorough read, it makes no sense for us to speculate on what it is or how long he'll be down."

With two outs in the ninth inning Monday, Grilli had thrown one pitch to Washington pinch-hitter Steve Lombardozzi before stalking around the mound in pain, and soon after he walked disconsolately off the field.