Luke Weaver injured his hamstring preparing for Sunday's game against the Los Angeles Dodgers, potentially costing the New York Yankees their star closer for over a month.

New York Yankees closer Luke Weaver is expected be placed on the injured list after injuring his hamstring warming up Sunday night, sources tell ESPN. Weaver underwent an MRI and could miss four to six weeks, though the official timetable will be determined Tuesday.

The New York Yankees could be without their top reliever for more than a month. Righty Luke Weaver strained his hamstring while warming up for the ninth inning of Sunday's win over the Los Angeles Dodgers (NY 7,

Ryan Yarbrough limited baseball’s best offense to four hits over six innings, Ben Rice hit a tiebreaking two-run homer and the New York Yankees defeated the Los Angeles Dodgers 7-3 to avoid getting swept for the first time this season.

Despite taking two of three games against the Yankees, the Dodgers continue to show some worrying signs as they enter one of their toughest stretches of the season.