Updated

Pittsburgh Pirates closer Jason Grilli left in the ninth inning of Monday's game against the Washington Nationals with an apparent arm injury, though the extent has not yet been determined.

Grilli, who came into the game with an NL-leading 30 saves and recently appeared on the cover of Sports Illustrated, threw a pitch to Steve Lombardozzi with two outs and walked off the mound clearly in pain.

The All-Star motioned to the team trainer in the dugout and exited with his head down following the quick visit. The team announced on its website Grilli was dealing with forearm discomfort and will be re-evaluated Tuesday.

"We're going to have to wait to see what the test results are," Pirates catcher Russell Martin said when asked of Grilli's injury. "It's a definite blow...but hopefully it's something minor."

The Pirates wound up winning the game, 6-5, after Vin Mazzaro finished off the save. Grilli had served up a two-run homer to Jayson Werth earlier in the ninth.