Nationals manager Matt Williams said Monday that infielder Anthony Rendon has been diagnosed with an oblique strain.
Rendon had been working his way back from a knee injury suffered in spring training before being sidelined last week with tightness in his side. He was sent back to Washington, D.C. to visit with the team doctor about his new injury.
With the new oblique issue, Rendon will have the timetable for his return set. He doesn't figure to return to action until the last half of May at the earliest.
"We're going to have to slow his progress down a little bit," manager Matt Williams said after Washington's 6-4 victory over the Marlins Monday, per MLB.com. "He's felt it for the last few days, so we're going to sit him a little bit longer and make sure it's OK before he resumes activity. It's just not getting loose for him."