A 36-year-old former youth football coach is slated to be arraigned Monday in Leominster District Court after an investigation led to charges that he sexually assaulted a boy, prosecutors said. Benjamin B. Brause of Leominster was arrested Friday night and charged with two counts of statutory rape and one count of indecent assault and battery on a child under 14, Worcester District Attorney Joseph D. Early Jr.’s office said in a statement. Brause is being held on $100,000 bail at the Leominster Police Department, police said. A police dispatcher denied a reporter’s request to speak with Brause on the phone. Brause coached youth football in Leominster starting in the 1990s and continuing until 2008. He was a coach in Lunenburg in 2009 and 2010, the statement said. Leominster police ask anyone willing to talk about their interaction with Brause to call them.