After meeting yesterday with Joel Hanrahan, manager John Farrell thinks the Red Sox have identified a reason for the embattled closer’s early struggles. Hanrahan has been dealing with soreness in his right hamstring since his second appearance of the season in New York, Farrell revealed before yesterday’s game. And although Farrell termed the situation “manageable,” he conceded that it has impacted Hanrahan’s mechanics, specifically the drive he has been able to generate with his legs. As a result, the Red Sox don’t intend to use Hanrahan for the next few days. Farrell said it is premature to determine if Hanrahan will have to go on the disabled list. Hanrahan said he informed the training staff, but not Farrell or pitching coach Juan Nieves, after tweaking his hamstring during a scoreless ninth inning April 3 at Yankee Stadium. He dealt with the same injury in the same spot last season with the Pirates and missed only a few games. Based on that experience, and with the Red Sox having several days off early in the season, Hanrahan hoped he would be able to pitch through the discomfort. Ultimately, though, Hanrahan said the issue has been a distraction, particularly during his last two appearances in which he has allowed two homers and walked four of the past five batters. On Saturday, Hanrahan walked the first two batters of the ninth inning before being lifted by Farrell, who said his knowledge of the hamstring issue contributed to the decision. “It’s kind of been there every game and just gotten progressively worse,” Hanrahan said. “You’re not able to repeat your delivery when you’re worried about your hamstring, if it’s going to pull, if it’s going to grab. It’s in the back of your mind. If you’re driving down the street thinking about hitting a car, you’ve got a better chance of hitting a car.”