"There was a car accident with one of his family members. I'm waiting to hear from [Rodriguez] to see how he's doing. It's pretty serious," Rodriguez's agent, Paul Kinzer, told the New York Daily News. "I found out [Wednesday] night. Hopefully it works out."
Kinzer told the Daily News that the brother was hospitalized, and ESPNNewYork.com reported that he is expected to be fine and that Rodriguez plans to return to New York on Sunday, according to sources.
Kinzer said he believed Rodriguez would be back in time for Monday's season opener against the Marlins at Citi Field.
"I know he's planning on being there for Opening Day," said Kinzer.
General manager Omar Minaya said on Thursday: "We expect to have him available" for Monday. But Minaya hardly was certain.
The Mets are scheduled to work out at Citi Field on Sunday.
Rodriguez's absence from a bullpen still unsettled would create a great unknown. As of Thursday morning, the club hadn't decided who will fill the eighth-inning role.