By Annie Maroon/DFP StaffLess than two months ago, Ben Rosen was facing Joey Diamond as an opponent when the Boston University men’s hockey team played the University of Maine. Now, as Rosen tries out for the Bridgeport Sound Tigers of the AHL, he’s rooming with Diamond, who signed with the Tigers this month and led Hockey East in penalty minutes this year.Rosen has signed an amateur tryout contract with the Tigers, the New York Islanders’ AHL affiliate, and practiced with them for the first time today at 10 a.m. He and Diamond, both Long Island natives, knew each other from playing against each other before college. “We kind of were rivals back then, and as we got older, we started to become more and more friendly, and actually, we’ve been friends ever since,” Rosen said on the phone from outside the hotel room the two are sharing. “So we would play Maine, and I would hate him when we would play them, but … he’s a great kid whenever you’re not playing against him, that’s for sure.” Rosen said he’s received other offers from ECHL teams but wanted to give the Tigers, the only AHL team to make him an offer so far, a shot. “My agent just said this was the quickest and the best offer we had, so I just took it right away,” Rosen said. “It was only a day or two after the season had ended.” If the Tigers sign Rosen to a contract, he would be in the farm system of the NHL team closest to his home in Syosset, N.Y. Rosen also attended the Islanders’ draft camp in July 2011, so he has some familiarity with the organization. “Even where the AHL team is, here in Bridgeport, I’m only an hour or so from my home on Long Island, so it’s definitely a huge factor,” Rosen said. “It’s close to Boston, it’s close to home in New York, and it’s a great opportunity.”