Nationals stretching out Roark in Minors

WASHINGTON -- Right-hander Tanner Roark was optioned to Class A Advanced Potomac on Tuesday with a specific agenda: increase his pitch count.

"It gives him an opportunity to stretch out a little bit not knowing how the whole month of September is going to go, and it prepares him for starting if we need to have him do that," Nationals manager Matt Williams said before Tuesday's opener against the Padres. "Potomac gives him the opportunity to be close, and we're not necessarily concerned with the competition that he's going to face. It's about increasing his pitch count."

With starter Joe Ross on an undisclosed innings limit and a corresponding move for Denard Span's activation off the disabled list necessary, the Nats decided to option Roark, a former 15-game winner, and stretch him out.

That said, with Ross showing no signs of tiring -- he went seven innings and allowed one earned run on Saturday -- it is unclear exactly when he will be shut down and the Nats will need another starter.

"We have to make sure that if in fact Joe is at his limit sometime in September, then we have somebody that's prepared to do it," Williams said.

The plan is for Roark to make two starts with Potomac before returning to the Nationals for the final month of the season.

"He'll start at somewhere around 60 [pitches]," Williams said. "He can be to 60 and then to 80 from there, depending on how he feels. Again, it's going to be limited for him, and the results are not an issue. We just want him built up."

Roark has flipped between the bullpen and the rotation several times in his career, including this season when he opened the year in the bullpen, filled in as a spot starter and was moved back to the bullpen.

Roark is 4-4 with a 4.54 ERA in 2015. In six starts this season, he went 3-1 with 21 earned runs allowed in 33 2/3 innings (5.61 ERA).