NEW YORK -- The New York Mets have lost five of their last six games and one-third of their starting lineup to injury, including their best player -- left fielder Yoenis Cespedes.
Now for the really bad news: The red-hot Washington Nationals are coming to town.
The Mets and Nationals square off Friday night in the opener of a pivotal early-season three-game series at Citi Field.
The National League East-leading Nationals (10-5) have won four straight and completed a three-game sweep of the Atlanta Braves on Thursday with a 3-2 victory. They are 2 1/2 games ahead of the Mets (8-8), who fell to the Philadelphia Phillies 6-4 on Thursday.
"Obviously, when you're chasing a team, it's nice to try to make up some ground," Mets manager Terry Collins said. "They're not ultimately the most important games that we're facing, but we certainly know they're looking at (the games) saying, 'We can increase the space here.' We don't want that to happen."
The Mets' task grew taller when Cespedes suffered a left hamstring injury while running to second base in the fifth inning Thursday night. Cespedes, who said it felt like a "shock" in his hamstring, is scheduled to undergo an MRI on Friday, though both he and Collins are hopeful he will miss only a couple of days.
The Mets also will likely be without first baseman Lucas Duda (left elbow) and backup first baseman Wilmer Flores (knee infection) Friday. Catcher Travis d'Arnaud, who was limited to pinch-hitting duties Thursday because of a right wrist contusion, could return to the lineup.
"We'll grind it out -- we always have, we always will," Collins said following the game Thursday. "We know what we're up against. We know they've got a good team. We've just got to pull it together. We have in the past. I don't know why we can't do it tomorrow."
The Nationals may also be at less than 100 percent for at least the start of the series. Shortstop Trea Turner, who is on the 10-day disabled list with a hamstring injury, is expected to rejoin the club Friday, though he may not be activated until Saturday. Left fielder Jayson Werth (groin) and second baseman Daniel Murphy (right leg) both sat out Thursday.
The incomplete lineup hasn't slowed the Nationals, who have scored 26 runs during their winning streak -- thanks largely to a resurgent performance from Ryan Zimmerman. The first baseman is 7-for-12 with two homers and seven RBIs in the last three games.
Zimmerman batted only .242 with 36 homers and 157 RBIs over the previous three seasons, a stretch in which he was limited to 271 games by a variety of injuries.
"No. 1, he's healthy," Nationals manager Dusty Baker said. "He's not missing balls. His concentration is high and he feels good about himself. It's been a tough last couple years."
Mets right-hander Jacob deGrom is scheduled to face Nationals right-hander Tanner Roark on Friday.
DeGrom doesn't have a decision in three starts this season despite a 1.89 ERA. In his most recent start, against the Miami Marlins on Saturday, deGrom tied a career-high by striking out 13 batters but saw the bullpen blow a 4-2 lead in the eighth inning. DeGrom is 2-2 with a 3.12 ERA in seven career starts against the Nationals.
Roark, who is 2-0 with a 3.50 ERA, didn't factor into the decision in his most recent start Saturday, when he gave up two runs over seven innings in the Nationals' 4-2 loss to the Phillies. He is 6-2 with a 2.47 ERA in 15 career games (nine starts) against the Mets.