Eckstein said he was hurt running the bases before he was thrown out at the plate while trying to score from second base on Nick Hundley's single to center in the first inning. Melky Cabrera's throw to catcher Brian McCann beat the sliding Eckstein to the plate.
Eckstein said he may be placed on the disabled list after his second right calf injury of the season.
"It's definitely being considered," he said. "It's rough, especially during this time. That's the frustrating part."
Information from The Associated Press contributed to this story.