Why aren't the Nats saving Strasburg's innings for later this season?

Twice already this season, rainouts have allowed manager Davey Johnson the opportunity to skip Stephen Strasburg in the rotation. With Strasburg's innings adding up and his team-imposed limit of somewhere around 160 innings this season looming, Johnson could choose to jump Strasburg in these situations and throw Gio Gonzalez on normal rest. That would allow him to save Strasburg's innings for later in the season, when the Nationals will hopefully be fighting for a playoff spot. Both times he's had the chance to skip his ace, Johnson hasn't gone that route. Instead, he's bumped all his starters back a day, keeping the rotation in order and pitching Strasburg on six days rest. Johnson was asked today if he's considered the alternative. "Yeah, that question has been brought to me," Johnson said with a wry smile. "I guess, call me old-school or whatever, but I believe in putting my best foot forward, wherever I can put it forward. And that's having Stras pitch on a regular basis. Looking at it from a player's viewpoint, I wouldn't want it any other way if I was a player. "We're kind of committed to his long-term future, so we're going to limit the innings, but how do you draw the line? Have him ready to finish the season and not the playoffs? Then you risk the chance of us not getting in the playoffs by not putting your best foot forward (now). So you can answer all those emails from all the irate fans wondering why we don't have him 'til the end of the year so I don't have to do that." In Johnson's mind, a win now means the exact same as a win in August or September. And he's certainly right in that regard. Some Nationals fans might prefer to see Strasburg on the mound pitching with the National League East pennant on the line, but there are no certainties in baseball. The only thing Johnson knows is that his team is playing well now, and he feels his best chance to win on any given day is to have Strasburg on the hill. That's why he'll keep sending his ace out there every fifth day until the powers that be tell him Strasburg is shut down for the rest of the year.