WASHINGTON -- The Nationals are entering a particularly grueling portion of their schedule over the next two weeks, a stretch that could serve as a potential measuring stick to the rest of the National League. Monday night kicked off a 14-game stretch against teams expected to have serious postseason aspirations, as the first-place Cardinals arrived at Nationals Park for the beginning of a four-game series.

Yet, series openers have been an issue for the Nats to start the year. After dropping Monday’s game to St. Louis, 6-3, Washington is now 1-9 in the first game of a series, a record that in some ways is fluky, but also represents the uphill battle the Nationals have been trying to overcome all season.

“I don’t know, we're not playing well right now, I think that's apparent,” right fielder Adam Eaton said. “When you don't play well, you don't win too many games, I think that's kind of what it's boiling down to.”

No, the Nats are not playing anywhere near the level which they expected to reach at the start of the year. Monday’s loss was their seventh in the past 10 games, pushing their record to three games below .500 at 12-15. Meanwhile, the Cards are clicking to start the year, winners of eight of their past nine games.

Patrick Corbin, who has been the team’s most consistent starter so far, cruised through the first four innings of his outing before the Cardinals erupted for a six-run fifth. The last time Corbin surrendered that many runs in a single outing came on May 30, 2018, against the Reds. Then, the Cards' pitching staff shut down the Nationals' offense, retiring 12 consecutive batters from Yan Gomes’ one-out single in the fourth inning until Juan Soto’s one-out walk in the eighth.

“It's a good offense over there,” Corbin said. “They have a lot of guys with some power, so you gotta minimize mistakes there. I put myself in trouble with those couple walks there and kind of just led to a big inning for them.”

To get through this stretch, the Nats will need their entire team to get on a roll, which they believe they are on the verge of doing. Their starting pitching staff is arguably the most reliable portion of their team. Even though three-fourths of their infield is currently sidelined -- Anthony Rendon was once again not available but not on the injured list Monday -- their lineup is still a threat. And their bullpen, their Achilles' heel up until this point, has recorded 12 consecutive scoreless innings.

“That could be a carryover,” manager Dave Martinez said. “They are starting to pitch like they are capable of pitching.”

The season is still young, with plenty of games left to play, but this stretch could go a long way toward defining who the 2019 Nationals are. It could prove to the Nats that they still belong with the league’s elite, or push them farther back as they look to overcome a slow start.

After this series with the Cardinals, the Nationals begin a 10-game road trip with the NL East-leading Phillies; the Brewers, who played in the NL Championship Series last October; and the Dodgers, the back-to-back NL champs and the team with the best record in the Senior Circuit.

“Some people see mountains, they get kind of daunted. We're excited to climb the mountain,” Eaton said. “We talked about it ever since Spring Training. If you want to be really good in this league, you have to beat the best teams. We're getting tested early and we're going to find out what we're made out of right off the bat. I think the guys in here wouldn't have it any other way.”