Last Year's Discussion
At that point Revere hadn't been traded for so the presumed plan was Werth, Bryce, and MAT getting his shot in CF. Why MAT? We thought it was clear the Nats wanted him as the CF of the future and that he did well enough in 2015 to get a chance. Span was dismissed because the QO was too expensive for a guy that couldn't play much in 2015.
I thought playing Werth was reasonable given his late season performance and the reality of the Nats situation. If you play Werth than a strong fielder in CF is the better play and that was Taylor not Span. I did however, say they should try to get Span on a team friendly deal as giving MAT another year of seasoning wouldn't be a bad idea. Failing that, I advocated for a strong OF bench to compensate for Taylor.
How did it play out? Well first off the Nats traded disgruntled closer Drew Storen for Ben Revere, which essentially re-demoted MAT for two seasons unless he busted out. It seemed like a smart move at the time but Revere would get injured early and would never hit like himself putting up a .217 batting average when he averaged ~.300 over previous 4 seasons. MAT failed to capitalize and hit exactly as he hit in a cup of coffee in 2014 and 130 games in 2015. Very low average (.231), some pop (7 homers in 76 games) too many strikeouts (32.5% rate - would have been 2nd worst if he had enough at bats). It was so bad that SS of the future, Trea Turner was moved to play CF and he was so good! .342 with 14 doubles, 8 triples and 13 homers and 33 stolen bases. In just 73 games he was ROY good in any year that didn't happen to have a rookie that was also a legit MVP candidate.
Surprisingly Bryce was an issue. A dip was to be expected but Bryce didn't just dip he dropped below what you probably would have had as his floor. A mediocre .243 batting average and only 24 homers. Injuries and mind games (PETE MACKINNON STARTED mind games) caused a stumble early in the year and what HAS to be a lingering shoulder-area issue hampered his second half.
On the plus side Werth bounced back with an acceptable year at the plate. It was a lot of bouncing around with punctuated moments of hot play but that was enough for an old player coming back from an injury that lost him a productive 2015. Still a stiff in the field.
All in all it didn't work but the CF and Bryce issues were fairly surprising so it's hard to fault the Nats.
Werth in LF. Bryce in RF. Something new in CF.
Reasoning on Presumed Plan
Werth hit well enough to take his last year in the field. Circumstances with Zimm mean that can't be at first so LF is where it's going to be. Generally you might see Rizzo move this type of player for something that could help the Nats in the future, but the contract makes Werth untradeable. You could argue a fading 38 year old starter should be replaced anyway but on the surprisingly long list of the Nats fixable issues, this doesn't even register.
Bryce starts because even crashing through the floor of his projections he was a useful bat and a solid, if unspectacular, corner OF. Given he's still under team control he's a bargain. You just have to hope he's healthy and you see a big increase in performance next year.
On CF we just don't know yet. We know they'd prefer if Turner played SS. They've now floated out there that Danny's available in trade. It would be very hard to go into next year with either Revere or Taylor or some sort of platoon as Plan A given how badly that failed last year. That leaves them to do something different. A trade is most likely given what the Nats are selling as their payroll limitations, but don't rule out a FA signing if they can get that money deferred. Unlike catcher I don't see the options being that limited and thus really can't put a finger on exactly what they will do.
Problems with Presumed Plan
Bryce could be hurt again and if so he won't put up the numbers you hope. That'll hurt planning as the Nats are probably looking at Bryce to be a star at the plate again. You just have to roll with this possibility. The guy put up literally "best ever" numbers the year before and just turned 24.
I did just say you might want to replace a fading 38 year old, didn't I? Werth shouldn't be better than last year in 2017. That's nothing against him, that's just the reality of aging. If he's just a little worse so be it. If the crash comes you now have an OF who can't hit or field in your line-up. As concerned as you may be with Espy at SS or Zimm at first, neither is likely to be the complete zero that Werth would be in this scenario. You also have to accept he could get injured again. The grind (NOW IN PAPERBACK!) wears even young men down.
We can't really judge the solution to CF until we see it but we can say that solving CF will cost you, either money or prospects, potentially both. If it does include money then the Nats have less to spend on other issues a lot of us see as more pressing - C, 1B, closer. If it does include prospects, the Nats minor league system isn't particularly deep. Any scraping off the top would have a serious effect.
You have to start Bryce. That's not even a discussion. But please just stop with the "he's healthy" shenanigans. You are not fooling anyone.
Moving to Werth, the Nats aren't inclined to replace something that's working passably just to do it and his bat is still passable as of the end of last year. You could move him to first and get a new corner OF as part of a play to sit Zimm, but it doesn't appear that the Nats are at that point yet. So the Nats will have to just accept his OF play and pray his body holds up and his bat doesn't drop any further. The bright side is Werth has proved very resilient and the Nats are only asking for one more year. It's not a good gamble, but there are certainly worse ones to take.
On CF? I would love to trade for McCutchen. Gambling on an MVP type coming off a bad year at 30 years old is a good gamble. Certainly a better gamble than Victor Robles becomes anything like McCutchen in the majors. I mention Robles because that is apparently what the Pirates want for McCutchen. That is a lot yes. He'll probably be the top prospect in the Nats system. But if you were trading for McC after a year like 2015 Robles wouldn't be enough. If you like McC, and I do, then Robles for him is a deal you make. His contract is not onerous. He still has power and some speed. While he's probably a below average CF at this point, his defensive failings were likely exaggerated in the stats.
Failing that the Nats need to go after a strong defensive CF. Leonys Martin would make an interesting target and is the kind of under control payer Rizzo likes. However his hitting is likely to be barely better than Revere/MAT. Dexter Fowler has developed into a strong bat, but even positioned correctly is probably just an average CF. Kevin Keirmaier is probably the ideal target but I have to believe the Rays know what they have there and it'll cost Nats more than they want to give. What does that possibly leave? Lorenzo Cain. FA after next season. Unlikely Royals keep him. Not a terrible contract (11 mill). You are just paying him to hit / field like you wanted Revere to, but at least he did it last year and you don't have to pay Revere. You can cut him.
Out of the Box Idea
I've got a wickedly terrible idea today. The Nats pursued this guy and last year and came up short but he's available this year. I assume. That last note should tell you I'm not talking about Yoenis Cespedes* but Jayson Heyward. This year and that contract should make him easily obtainable from a team that doesn't really need him. Are you making an insane gamble? Yes, yes you are. But with that D and his age he's not going to be worthless for a few years. He could be the very good CF this year and shift to be a great corner OF for a few more. Assuming his struggles at plate continue, that's the worst case. The best case is that his problems this year were a combination of fluke and fixable and you can get him back to a more normal bat. If the Nats, and a lot of teams, liked him before last year there must be something there. It's just a question of if the bat can be brought back to life.
*What do I think of Yoenis? Not a good CF, would make the team better, very doubtful he signs here unless deferred money thing doesn't exist anymore.