NEW YORK -- Before Thursday's series finale between the New York Mets and Washington Nationals, Mets manager Mickey Callaway announced two more additions to the team's growing list of players on the injured list. Both Robinson Cano and Jeff McNeil have landed on the shelf.

Cano exited Wednesday's game with tightness in his left quad after running out a grounder. The injury came just days after Cano was criticized for not hustling. McNeil wasn't in the lineup for Wednesday's game because of tightness in his left hamstring, and it wasn't feeling much better in time for Thursday's game.

"[McNeil] hasn't had an MRi but [the hamstring] is tight enough to where we have to be cautious here," Callaway said Thursday afternoon. "To run him out here wouldn't be productive so we're going to continue to monitor him for the next couple days and then try and figure out what needs to be done from there."

McNeil said that his hamstring tightness is still there, and that he doesn't mind a stint on the IL. "We're just going to play it safe," McNeil said. "We don't want it to become a bigger issue. I tried to play through an injury, ended up tearing my quad and missing two and a half months so I don't want this to become something big."

The latest injuries -- including Michael Conforto's concussion -- put Callaway in the Mets in a tricky spot. They'll have to use J.D. Davis, Juan Lagares and Carlos Gomez in the outfield. They also have veteran Rajai Davis, who homered in his first at-bat with the team on Wednesday. As for second base, Callaway says that they'll play the position day-to-day. Adeiny Hechavarria started at second in Thursday's series finale. 

The Mets now have Cano, McNeil, Brandon Nimmo and Michael Conforto all on the injured list. Infielder Jed Lowrie and outfielder Yoenis Cespedes also sit on the IL, and both have yet to play a game this season. Cespedes' outlook for returning to the field this season is pretty bleak after the news of his broken ankle.

New York called up infielder Luis Guillorme and left-handed relief pitcher Ryan O'Rourke from Triple-A Syracuse to take Cano and McNeil's roster spots.