The Washington Nationals will use a closer-by-committee approach while Rafael Soriano seeks to correct the flaws in his delivery.

Soriano has a 6.98 ERA since the All-Star break and has given up at least one run in seven of his past 12 outings.

"His fastball velocity is good, the command isn't quite where he wants it, certainly," Matt Williams said. "The slider, the depth of his breaking pitch, is not there right now."

Washington has a seven-game lead in the National League East.