When the Mets faced the Nationals last week, they found themselves with an opportunity to gain ground on a first-place team that was eight games ahead of them entering the start of the three-game series.
But after winning the first game, New York dropped the next two and fell to nine games out. Now the Mets are close to where they were last week, 7 1/2 games behind the NL East leaders. The only difference is that this time, they're taking on the Nationals at Citi Field, where they're 3-4 in the second half.
The Mets had their best shot of getting a head start on Washington with another strong outing from rookie Jacob deGrom. But the right-hander with the 2.87 ERA in 16 Major League starts will not take the mound on Tuesday. He experienced shoulder soreness following his start on Thursday against the Nationals, in which he allowed three runs on seven hits in six innings. He was placed on the 15-day disabled list on Monday with right rotator cuff tendinitis.
"I could probably go out there and pitch with it right now," deGrom said on Sunday. "But I think, just talking with [the team], at this time of the year, it's not really worth pushing it. If I can skip one and be 100 percent and let it calm down, that was what they kind of talked about."
In place of deGrom, right-hander Rafael Montero will get the start. The 23-year-old made his Major League debut on May 14 against the Yankees, and in four starts, went 0-2 with a 5.40 ERA. In 15 starts for Triple-A Las Vegas this season, he went 6-3 with a 3.28 ERA, striking out 75 and walking 32 in 74 innings.
Over his last two starts for Las Vegas, he tossed 14 2/3 scoreless frames and held opposing hitters to a .085 batting average.
"He certainly has the stuff that will play in the Major Leagues," said Mets manager Terry Collins, who expects Montero to make at least two starts. "He needs to throw strikes, and if he does that, he'll be here for a long time."
Meanwhile, New York's hitters will have to contend with Washington's top starter, Doug Fister.
Wednesday against New York, Fister proved why he is arguably the best pitcher on the Nationals' pitching staff. He was solid for 7 1/3 innings as the Nationals won the game, 7-1.
Fister won his team-leading 11th game of the season, allowed one unearned run and struck out seven batters. He started the game off by retiring nine of the first 10 hitters he faced. The Mets scored their only run after Fister left the game.
"I didn't quite get what I wanted," said Fister, who allowed six hits -- all singles. "But our guys played great defense. [Anthony] Rendon taking lines drives, [Jayson Werth] making sliding catches. Those are the unmentionables that make up a team."
Nationals: Werth's bat crucial to success in New York
Werth was back in the starting lineup Sunday, hitting third against Atlanta. He went 0-for-1 with three walks in the Nats' 3-1 loss.
Werth didn't start in either of the first two games of the series because he was dealing with right shoulder issues that he sustained after making a catch against the Phillies at Nationals Park last week. The injury grew worse as the Nationals played a 13-inning game against the Mets on Thursday.
Werth's return is bad news for the Mets because, amongst NL East rivals, the outfielder hits them the best. He has batted .299 with 14 homers and 46 RBIs in 124 career games against them.
That's been magnified this year, as he's posted a .389/.450/.444 slash line in nine games vs. New York.
Mets: Mejia to pitch despite hernia
Mets closer Jenrry Mejia told reporters after taking the loss in Sunday's 7-6 defeat against the Phillies that he recently saw a doctor about a hernia. He also said that he is taking medication for the associated pain and wants to finish out the season.
"The doctors have said he can pitch," Mets manager Terry Collins said. "As long as his arm feels fine, he can pitch."
Though the Mets found themselves in a save situation with a 5-2 lead entering the ninth inning of their eventual 5-3 win over Philadelphia on Monday, Collins elected to go with Jeurys Familia for the save.
Mejia is 5-5 with a 3.89 ERA and 17 saves this season.
• The Nationals have won seven of nine meetings with the Mets this season.
Maria Torres is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.