The National League East foes are scheduled to face off 12 times in the second half, including six of the next nine games. They will open the first of those sets on Tuesday night at Nationals Park, with the Mets having lost four straight to fall to 3-7 in July.
"Every game's important, but the thing is, we have a lot of games to play," Mets first baseman Ike Davis said before Sunday's 6-1 loss to the Braves. "We lose [three in Atlanta], but hopefully we're going to pick up and then go to Washington and string some wins together. [Three losses] in a row is not the biggest deal in the world. Obviously you want to win the games, but if we win 10 straight after this ... it comes in waves."
The Nationals hold a 4-2 advantage in the season series with the Mets, but each game so far has been decided by four runs or fewer.
Washington will start Ross Detwiler, who threw five shutout innings against the Mets in his season debut. The lefty has a 3.78 ERA in three starts since returning to the rotation, but gave up three runs on 11 hits in five innings on July 5 against the Giants.
"The bases were loaded, it seemed like, every pitch I threw," Detwiler said.
The Mets counter with another southpaw, Jon Niese, who will try to rebound from a rough start against the Cubs on July 8. Niese had posted a 2.17 ERA over his previous eight starts before Chicago touched him up for seven earned runs in seven innings.
"I felt like I made a lot of good pitches, and then when I had guys in scoring position, I made mistakes and they punished me," said Niese, who gave up four runs in the first inning and three in the seventh.
Nationals: Pine tar incident discussed
Marlins manager Ozzie Guillen and Nationals skipper Davey Johnson had a brief phone conversation following Sunday's game to clear the air.
During Washington's 4-0 win over Miami, Guillen and Nationals rookie Bryce Harper got into a chirping match in the fourth inning stemming from the amount of pine tar on the 19-year-old's bat. Guillen called Harper "unprofessional" for the way he handled the incident, and said Sunday that he would talk to Johnson about it later that evening.
"He called me," Johnson said. "He said it wasn't a big deal and enough said about it. It was an interesting exchange going on, but that's Oz. ... It was a pretty brief call. It wasn't a big issue with him."
Guillen had a different account of the conversation.
"I tried to call him, and he told me to get the [expletive] away from me," Guillen said. "I don't think Davey understands why I called him. I just called to say, 'I don't want to make a big deal about this. I just think he did something he shouldn't.' I love Davey and I think he is one of the best baseball men in the game."
Mets: Bay almost ready
Tuesday's game could be Jason Bay's first for the Mets since he suffered a concussion on June 15.
Bay played five rehab games for Triple-A Buffalo, including one on Monday. Even though he likely won't receive any time off between his rehab and his return to the Major Leagues, Mets manager Terry Collins said he isn't concerned about rest.
"He needs at-bats," Collins said. "This is about at-bats. I'm not worried about the fatigue factor. He's been out three weeks resting. I'm not worried about fatigue."
Bay, in the third year of a four-year, $66 million contract, is hitting .187 with a .626 OPS and four home runs in 22 games.
Right fielder Lucas Duda will get his strained left hamstring examined by a doctor in New York on Monday, but Collins doesn't believe the injury will require a trip to the disabled list.
The Mets have won two of three games in Washington this season.
Niese has a 2.19 ERA in two games at Nationals Park.