Seibu Lions manager Kazuo Matsui will take an indefinite leave of absence, with general manager Hisanobu Watanabe stepping in as interim manager, the struggling club said Sunday. Seibu is currently last in the six-team Pacific League standings with a 15-30 record in the former MLB infielder’s second season at the helm. The Lions finished fifth in 2023. The Lions had their eight-game skid snapped only Saturday. “I feel the players are developing, but it’s my responsibility that we have not been able to turn that into wins,” said the 48-year-old Matsui, who played for the New York Mets, Colorado…