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.After throwing 14 pitches in one inning during an 18-2 loss to the host Los Angeles Dodgers on Saturday, Weaver stopped warming up to pitch the ninth inning of New York’s 7-3 win on Sunday due to hamstring discomfort.New York manager Aaron Boone told reporters after the game that Weaver would undergo testing, and ESPN reported that the right-hander underwent an MRI. Per the report, the length of Weaver’s absence will be determined on Tuesday.The Yankees, who lead the American League East by 5 1/2 games, open a three-game series against the visiting Cleveland Guardians on Tuesday.Weaver, 31, has excelled out of the Yankees’ bullpen this season, going 1-1 with a 1.05 ERA and 0.701 WHIP in 24 games spanning 25 2/3 innings. He took over for struggling closer Devin Williams in late April and has eight saves in nine chances this season.