Wilson Ramos expects to be placed on the 15-day disabled list with a right hamstring strain. (John McDonnell/The Washington Post)

The Nationals placed oft-injured catcher Wilson Ramos on the disabled list for the second time this season with a Grade 1 right hamstring strain, Manager Matt Williams said. Williams said doctors expect him to recover within seven to 10 days, but Ramos’s latest injury will subtract a powerful bat from a lineup that finally had grown healthy.

“I’m positive,” Ramos said. “It’s hard for the manager to make that decision. They need to have two healthy catchers. I understand that.  They need to have somebody 100 percent on the bench in case Lobie gets hurt. I want to work. I want to keep working and do my treatment right.”

Ramos underwent an MRI on Tuesday afternoon, and the test revealed the strain. Ramos had hoped he could avoid the disabled list, but he will be sidelined too long for the Nationals to play with only one catcher.

“If it was a couple days and he’d be fine, it’d be one thing,” Williams said. “We just want him to get it taken care of and he’s back in 15 [days]. The thing we don’t want him to do is get back out there and hurt it worse, and then you’re talking 30 days.”

Ramos already missed 32 games this season after he broke the hamate bone in his left hand opening day. With both him and Ryan Zimmerman back in the lineup, the Nationals’ offense had been amongst the best in the majors. Ramos hit two doubles Tuesday night before he exited the Nationals’ victory.

“His swing has been really good lately,” Williams said. “So that’s disappointing.”

Jose Lobaton, who is hitting .224 with a .643 OPS, will take over as the Nationals’ starter until Ramos returns. The Nationals summoned Sandy Leon from Class AAA Syracuse to serve as Lobaton’s backup. Leon had arrived from the East Coast in time for Wednesday night’s game, sparing utility man Kevin Frandsen from having to serve as the Nationals’ emergency catcher. Wednesday afternoon, just in case, Frandsen strapped on shin guards and caught Jordan Zimmermann’s bullpen session.

Tuesday night, Ramos left the Nationals’ 2-1 victory with what Williams called “tightness” in the hamstring. He felt a twinge in his hamstring as he neared second base while legging out a double. He slid into second base, and when he stood up Williams and head athletic trainer Lee Kuntz came to check on him, then escorted him off the field.

Last season, Ramos spent two stints on the disabled list, including one that lasted roughly two months, with left hamstring strains. The injury he suffered Tuesday felt far less serious than either of those pulls, he said. Still, Ramos has been sidelined three times in two years with hamstring injuries. He plans to alter his conditioning program to avoid future pulls.

“Maybe I need to work just my hammy,” Ramos said. “Because I don’t have anything wrong with any part of my body other than my hammy.”

Williams said he would not restrict Ramos from running hard on the bases.

“I don’t think you can stop that,” Williams said. “Guys play the game, and they read whatever is going on out there. … It’s probably a function of being out for so long with his hand and tryig to get back in the mode of playing. A lot’s been dumped on him. We tried to give him days off, but on the bases, he’s had to go first to home a few times. He’s hit a lot of doubles. You can’t take away the way they play the game.”