"We didn't want to take any chances in that situation," Williams said after Sunday's game. "We'll have to see how Asdrubal is when he wakes up tomorrow when we get him to the ballpark. Just a little bit of tightness, so we want to be cautious in that regard."
If the injury does force Cabrera to miss time, Espinosa will likely receive starts at second base over the next week, as could utility man Kevin Frandsen.
Espinosa was in a starting role at second base earlier this season when Ryan Zimmerman was sidelined for 44 games with a right thumb fracture, but he struggled mightily from the plate and saw his season average dip close to .200. So when Zimmerman went down again in late July with a Grade 3 right hamstring strain, the Nationals opted to trade for the veteran Cabrera instead of returning Espinosa to the starting lineup.
Even so, during August, the switch-hitting Espinosa has gotten spot starts against lefties because of his solid splits from the right side of the plate -- he's hitting .298 as a righty and .183 as a lefty.
Now, there's a chance Espinosa will have to resume full-time starting duties, which he said he's continued to prepare for on a daily basis by upping the velocity on the pitching machine in the cage, among another things.
"The role this year has been when guys get hurt, being in there every day," Espinosa said. "And if not, just have to keep your head up and keep grinding and keep doing what you can to maintain your swing and maintain game speed."
In his first at-bat Sunday after replacing Cabrera, which came from the right side of the plate, Espinosa scooted a ground-ball single up the middle. Perhaps more importantly, in his second at-bat, the second baseman crushed a left-handed two-run home run over the right-center-field fence.
It marked Espinosa's first extra-base hit from the left side of the plate since July 21.
"I've done it before so I know I can do it." Espinosa said of his lefty batting. "I know it's there."
Daniel Popper is an associate reporter for MLB.com. He also can be found on Twitter @danielrpopper. This story was not subject to the approval of Major League Baseball or its clubs.