Nats waiting to reveal NLDS starters

Williams wants to observe Zimmermann on Sunday before making final call

Nats waiting to reveal NLDS starters

WASHINGTON -- The Nationals will finish the regular season on Sunday against the Marlins, and manager Matt Williams indicated on Thursday that he will wait until then to reveal his starting rotation for the National League Division Series.

Right-hander Jordan Zimmermann is scheduled to start the finale against the Marlins, eight days after he suffered a bruised right shoulder thanks to a line-drive comebacker. While Williams doesn't expect any health problems, he doesn't want to commit to anything until seeing Zimmermann pitch.

"We want to make sure that [Zimmermann is] good, and we'll wait through Sunday and make sure everything is OK," Williams said. "Then we'll be able to move forward from there. I don't anticipate any issues."

In the meantime, Williams said righty Tanner Roark could potentially pitch out of the bullpen this weekend, since the reshuffling caused by Wednesday's rainout pushed him out of his scheduled start on Sunday.

Roark might pitch as a reliever in the playoffs as well, despite going 15-10 with a 2.85 ERA in 31 starts this season. The Nats have four more experienced options, and the rotation is now lined up in a way conducive to using Stephen Strasburg in Game 1 of the NLDS, followed by Zimmermann, Doug Fister and Gio Gonzalez. Williams, however, said Roark's role could depend on Washington's opponent, as well as how other players are feeling.

"That's up in the air," Williams said. "I'd imagine that's up in the air for everybody, because you just don't know where you're at in the course of a series. How are guys doing? Do you have some sort of hiccup over the weekend going in? A lot of things depend on how we come out of the regular season."

Roark is also in "uncharted territory," as Williams put it. He's shown no signs of slowing down, with a 2.45 ERA in September, but has thrown 198 2/3 innings. That's almost 40 more than the 27-year-old's previous career high (159 1/3), set last year at Triple-A Syracuse and Washington.

Andrew Simon is a reporter for MLB.com. Follow him on Twitter @AndrewSimonMLB. This story was not subject to the approval of Major League Baseball or its clubs.