As much as I'd like to say differently - it's not panic time. Neither team, the Nats or the Mets should really panic unless the gap between them approaches the number of H2H games they have left (6). Right now the Nats could match the Mets up to the H2H battle and get back into first with a single win.
There is still a lot of the season left, more than a third. The division could be won by someone running away but it's better to assume it will be close and if that's the case each win the Nats can get is of crucial importance. How can the Nats maximize wins?
At catcher : Make sure Lobaton doesn't hit against lefties.
There's been talk about letting Lobaton play more, but the truth is he is no better than Ramos. Not at the plate, and really not behind it either (past few years of pitch framing and caught stealing don't show me enough of a difference to get worked up about). So play him as much as you usually would. He's been Gio's personal catcher so keep that going I guess but don't let him hit lefties, even if Gio is pitching. He can't do it.
At first and second : Pray for health
I'm not saying either are "back" but both Rendon and Zimm look ok and are crucial to the success of the Nats. Give them a couple more weeks to see where they are while scouring the potential waivers for a worthy 6 week replacement for either. Probably unnecessary but no harm keeping an eye out.
At shortstop : Don't call up Tre Turner... just yet
I know you guys are all ready to replace him but Ian Desmond has hit .300 / .364 / .580 over the past two weeks. He battled through a 1-16 stretch in there, and came out the other side with a hit in each of the last 3 games. Espinosa? Obviously you haven't paid attention because Danny has been hitting like old Danny since well before the All-Star break. He's not the answer. Tre Turner is looking great in AAA, but Tre Turner performance at the major league level is a great unknown. Do I think he'll be good in the majors? Looks like it. Do I think he'll be good for 7 weeks if brought up now and made to start? Hell if I know.
Ride out Ian's return to relevancy for a few more days at least. If he keeps hitting ok, you can probably wait till September for Tre. If he flounders then call him up.
At third : Nothing.
Yuney had an unimpressive July but hasn't dropped enough for him to be a big worry. Just take him as is. If for some reason he does fall apart now in karmic retribution for some crazy BABIPs in May and June, it's just another reason to wait out Ian. If Ian hits and Yuney struggles, Yuney could be out. Not Ian. I'm not saying it's likely but it could happen. Yuney's been over his head.
In the OF : Get Span back ASAP, see where you are then, pray harder
There's not much that one can do. Robinson is not a "have to play" option, so Bryce, Taylor and Werth it is. If the prayers work Werth will return to having some sort of offensive presence and Span simply replaces the flailing Taylor. If the prayers don't work... well assuming nothing has changed, you probably split time between Taylor and Werth, with Taylor getting all the late innings and occasional spot start for defense.
In the rotation : Get Strasburg back ASAP, drop Fister. Ride out Ross as long as his arm takes you.
Fister hasn't looked good since May. He has a 4.86 ERA since coming back from injury and a 6.14 ERA in his last 4 starts. He's gotta be the one to go if you value winning. As for Ross and innings limits, don't think about it now. Maybe the division will be decided in a month when he hits it and you can pull him. Maybe he'll have tired out and look like he needs to stop. If neither are true you've gotta make the call to keep him going, in my opinion but let it go.
In the pen : Tell Storen he's the most important guy in the pen and as such you are going to use him wherever.
Storen has been jerked around because the Nats keep bringing in veterans who refuse to do anything but close and dammit if they can't make Storen do it. Let me take a moment to shed a tear for him. Ok done. It's not fair but that's life. What should happen now that instead of Storen being "8th inning hold guy" he needs to be seen as "Mr. Important situation in 7th inning on guy" That's his new "position". Make him feel important. Sing his importance from the highest mountain. Because it'll help him accept it, it'll be totally true, and it's best for the team. This way he can put out fires for starters, he can keep games tied that aren't going for saves, and yes, he can get holds when they come up. Use him like that and you won't need to work him in lost causes like last night. He'll get plenty of work.
Wrapping it up there's actually not much. Use Storen more effectively in more situations. Take Fister out when Stras is ready. Take whoever is worse, Taylor or Werth, when Span is ready. Watch Ian carefully and be ready to pull the trigger on Tre Turner. Scour the waiver wire for a no doubt bat in the OF or MI (Yuney can shift or sit) or an emergency bat. Pray. This team was already set-up for success, more than anything it just needs to perform like it was supposed to.