Roark invaluable to Nats success, and they know it

Right-hander Tanner Roark has been on a roll his last seven games as the Nationals maintain first place in the National League East. In his last six starts and one relief appearance, Roark has gone 4-1 with a 2.49 ERA in 43 1/3 innings. He has 31 strikeouts and only 10 walks in that span.

Tonight, he seeks his 11th win of the season when he takes on the Arizona Diamondbacks in Phoenix.

He is currently 10-6 overall with a 2.96 ERA. In his best season two years ago, he went 15-10 with a 2.85 ERA. His two-seam fastball is averaging close to 93 mph and has been the pitch that he can maneuver around the plate to get outs.

In his last start, a 4-2 win over the Giants on July 28 at San Francisco, Roark went seven innings and allowed one run and only four hits, with three walks and three strikeouts. He tossed 111 pitches, 64 for strikes.

Amazingly, the Giants' only run was on a groundout to first baseman Ryan Zimmerman. On the play, Zimmerman could have gone home to get the runner at the plate but elected to tap first for the out.

Roark survives innings like that and goes long in games. He has been a workhorse on the mound, having reached at least 108 pitches in eight of his starts.

With Max Scherzer, Stephen Strasburg and Roark, the Nationals have a formidable trio to stop teams from scoring in the playoffs. The Giants series was an example of a team they could face in the divisional round.

In the first two games, San Francisco managed just three runs. Roark would be a major part of the starting pitching for a series in the postseason. Right-hander Joe Ross could be that fourth starter, or used as formidable bullpen arm to bridge games.

The bottom line is Roark is extremely valuable to the Nationals. And the Nationals recognize his top value to their success. Last week, clubs that inquired about right-handers Lucas Giolito and Reynaldo Lopez as trade possibilities also asked for Roark's availability in a trade.

Roark was not made available by the Nationals as a trade chip, according to a league source.

Roark is invaluable to the Nationals and a top reason why they lead the NL East. Now they hope they can continue to use him in division-deciding and then postseason-winning starts.