McCutchen, meanwhile, reported his left knee felt "fine" Saturday and could return Sunday.
During the first inning of the Nationals' game against the visiting San Francisco Giants, star outfielder Bryce Harper's leg buckled as he touched first base. It was still raining when Harper's injury happened.
Harper flew in the air and appeared to be in agony as he hit the ground while clutching onto the front of his knee.
Harper slipped on the bag, had to be helped off field.
The game had been delayed for three hours because of heavy rains. Harper put no weight on his left leg as he was helped off the field.More news: J&K: Security forces and terrorists exchange fire at Shopian's Awneera village
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Major League Baseball was in control of weather decisions because it's the Giants' final trip to Washington this season.
Because of a bevy of injuries, the Nationals have used 12 outfielders this season. The league deemed the conditions playable after the rain slowed from its earlier levels, though the rain continued through the first inning.
For all of the Nationals' injuries this season, and there have been plenty of them, they have been able to avoid anything catastrophic since Eaton tore his anterior cruciate ligament. He played in 105 of Washington's first 113 games.
This story will be updated.