Nationals trying to balance health vs. home field

This is a tricky weekend for the Nationals. Yes, they would like to secure home field advantage for the National League Division Series against the Dodgers. They'd also like to do everything to make sure they're as healthy as possible for that five-game series with so much at stake.

How, then, to strike a balance between taking care of their bodies while also keeping a foot on the gas pedal?

"This is the time of the season, that's tough," left fielder Jayson Werth said after tonight's 7-4 loss to the Marlins. "Obviously we're playing for home field advantage, and that's important. But once you win the division, there's that exhale, that sigh of relief. To kind of put it in your terms: You kind of let off the throttle a little bit. Obviously, home field advantage is important to us, and we want that. But at the same time, we also feel like we've done our job a little bit. So there's a balance there. You err on the side of caution at this point. You don't want to do something where you can put yourself in jeopardy, where you can really get hurt."

Werth found himself right in the middle of that internal debate during tonight's game, when his back tightened up and prompted an early exit after seven innings.

The 37 year-old insisted afterward the injury wasn't anything serious, just tightness in his back and side, as opposed to a full-on muscle strain. But it was enough to convince him not to take any chances.

"It's one of those things where we're in a part of the season where you'd rather err on the side of caution," he said. "I just didn't want to put myself in a position where I could potentially get hurt. So I just talked to (manager Dusty Baker) and he got me out of there. More precautionary than anything else. If I'm not in there tomorrow, I'd be surprised. It's possible it could still be tight tomorrow, but I don't think we're dealing with anything that's anything other than tightness in there. I didn't strain anything. I didn't pull anything. When I came in, we did a bunch of tests, most of the tests with the training staff. And we ruled out any strains or pulls or anything like that. It's more of a tightness thing."

The Nationals have taken an especially cautious course of action with second baseman Daniel Murphy, who hasn't been in the lineup for nearly two weeks with a strained buttocks muscle. It doesn't appear the NL MVP candidate will play in either of the regular season's final two games, but the club figures that's a small price to pay to give Murphy as much time to heal as possible before Game 1 against the Dodgers next Friday.

The Nationals also were cautious with Bryce Harper, who sat out four games this week after jamming his right thumb on an awkward slide into third base Sunday at Pittsburgh. Harper did return to the lineup tonight, but the results weren't pretty: 0-for-4 with four strikeouts.

"I felt great tonight," said Harper, now batting .242 on the season. "I felt really good. Even with the four strikeouts. It happens. I missed some pitches I should've drove. I felt great."

In Harper's case, at-bats right now are more important than rest, and tonight's performance was evidence of that.

"He was rusty," Baker said. "We've got to get that rust off of him before we start the playoffs. We've just got to knock off the rust, and hopefully he can get it in the next couple of days. And if not, we've got a week for him to get it."