He has been out since Monday because of a sprained right thumb, which he injured when he dove after he took a poor route to a ball in a Grapefruit League game against the Yankees. Brown had X-rays on Wednesday, but he also had an MRI exam scheduled Thursday.
"We don't think it's anything serious, but we're going to take every precaution and get it scanned," Phillies assistant general manager Scott Proefrock said.
Brown sprained the same thumb last season diving for a ball with Triple-A Lehigh Valley, so the Phillies want to be cautious.
"That's why they want to look at it more closely," Proefrock said. "There have been some issues in the past and they're not sure what's new and what's old."
Brown is 2-for-8 with one triple and one walk in three games. He is expected to open the season in Lehigh Valley.