Five Nats who still have something to prove before October

There are team-oriented objectives for the Nationals over the season's final three weeks, but there also are individually oriented objectives that will help determine how this team looks once it reaches the postseason.

With that in mind, let's take a look at five players for whom this final stretch carries some extra weight, even with the Nationals having already clinched the division crown...

WILMER DIFO
The dynamic infielder is going to make the postseason roster; he has earned that spot with his performance all season filling in for Trea Turner and others. But Difo could help his cause even more if he proves he can be trusted to play the outfield, as well. And he may get several opportunities to do just that.

It was a minor move in the eighth inning of an 8-0 loss Tuesday night, but Dusty Baker had Difo replace Howie Kendrick in right field. The thought process: With Bryce Harper's return uncertain, and with Jayson Werth battling a sore left shoulder and Brian Goodwin still unable to return from a groin strain, the Nationals are short on outfield depth.

Could Difo end up being counted on as one of their backups come October? He certainly has a case for playing time ahead of less-experienced players like Andrew Stevenson and Rafael Bautista. But unless the Nats are comfortable with him defensively in the outfield, they can't make that move. The next three weeks could help them decide.

JOSE LOBATON
It's been a miserable season for Lobaton, whose .495 OPS is the worst among all major leaguers with at least 140 plate appearances. And his previously strong work behind the plate hasn't been there, either. FanGraphs rates him 52nd out of 57 catchers with at least 300 innings played this season in defensive metrics.

The Nationals are generally loyal to their veterans, and Lobaton has been an immensely popular teammate for the last four seasons. But the team owes it to itself to field its best possible team come October, and there's a reasonable argument that Pedro Severino (who started two games last postseason) is a better option to back up Matt Wieters.

Lobaton will continue to get some playing time down the stretch, but he may need to show something to convince club officials he deserves to stay on the roster.

VICTOR ROBLES
Everyone in the organization has been raving about Robles for years, and there has been a sense all along that he could be ready for regular playing time in the big leagues next season, as a potential replacement for Werth. But few expected him to be in the mix for playing time right now. That was, until Harper and Werth and Goodwin all went down.

Enter Robles, who at 20 is the majors' youngest player. It's still not an optimal situation, but if the Nationals see enough of him these next three weeks to believe he can handle the pressure, it's not ludicrous to wonder if he might crack the postseason roster as a backup outfielder who also has the speed to be used as a pinch-runner in key spots.

ENNY ROMERO
There was a point earlier this summer when Romero looked like a strong bet to make a postseason bullpen. But then he landed on the disabled list with a forearm strain, and suddenly he fell out of the spotlight. Now the flame-throwing left-hander is back healthy, and he's got three weeks to show the club he can still be trusted.

Romero has the stuff; that's never been a question. But can he develop enough confidence in his breaking ball to use it in big situations? He worked on that during a rehab stint with Triple-A Syracuse and upon his return said he feels much better about it now. But his first few appearances off the DL have been erratic. That's understandable, given the layoff. But he's running out of time to make his case and is going to have to show something soon.

JAYSON WERTH
Everything appeared to be great when Werth returned from a three-month stint on the DL with a bad bone bruise in his left foot and homered in his Aug. 28 return. But he's been struggling mightily since then, going hitless in his last 20 at-bats. And now he's been out of the lineup the last five games with a sore left shoulder (still barking after he was hit by a pitch during his rehab assignment).

Werth should be good to go in the next day or two, but he'll need to prove not only that he's healthy but that he can be productive again. It's been fair to wonder for a while now whether Werth's starting left field job (assuming Harper makes it back from his injury to play right field) is secure, given Kendrick's consistent production. Dusty Baker was asked about that Tuesday afternoon and was noncommittal, pointing out either way he'll still have a really strong bench.

Is it possible that the heart and soul of this franchise for the last seven years, with his contract about to expire, would lose his starting job now? Maybe not. But Werth has some work to do in the next three weeks to make sure he's helping the Nationals try to advance in the postseason for the first time from the field, not the dugout.