Antony said Buxton remains day to day, and he should return to action next week.
"I think they thought initially it would be two or three days, but they wanted to make sure they weren't missing anything, so they had the MRI," Antony said. "They expect him to back in there after going on some anti-inflammatories. They did not think it was anything to be concerned about."
Buxton, ranked as the No. 1 overall prospect by MLB.com, was reassigned to Minor League camp in the first round of cuts on March 9. The center fielder hit .158 (3-for-19) with a double and a homer in seven Grapefruit League games.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.