The Washington Nationals placed Ryan Zimmerman on the 15-day disabled list with a right hamstring strain on Wednesday. The team physician Dr. Wiemi Douguih has yet to interpret the results from Zimmerman’s MRI exam.

Zimmerman suffered the injury in the sixth inning Tuesday night running out a grounder. The Nats called up infielder Zach Walters from Triple-A Syracuse according to USA Today.

Zimmerman has missed 44 games this season on the disabled list due to a broken right thumb. The team is 33-19 with Zimmerman and 22-24 without him according to the Washington Post. The team also scores an extra 1.4 runs per game with Zimmerman in the lineup.

Nationals manager Matt Williams says Zimmerman is pretty sore and could miss some significant time. “When I spoke with him this morning, he hadn’t had any treatment on it. When you’re hot and it happens, it doesn’t feel quite as bad as the next morning when you wake up. But we’ll see what the results are,” Williams said.

Zimmerman is hitting .282 with five homers and 36 RBIS this season.