Mets second baseman Daniel Murphy has a pulled right hamstring and could open the season on the disabled list, GM Sandy Alderson said Friday.

Murphy departed Thursday's Grapefruit League game against the Cardinals after singling and scoring on a sacrifice fly in the top of the first inning. The team initially labeled the injury "tightness." An MRI taken Friday revealed the more extensive issue.

"He'll be out a week or so, maybe a little longer," Alderson said. "Hamstrings take longer than people want to admit."