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.

New York Yankees closer Luke Weaver, who sustained a hamstring injury over the weekend, is expected to be sidelined four to six weeks, ESPN reported on Monday night.

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.