Terence Crawford's move up to welterweight to challenge Jeff Horn for his world title on April 14 at Mandalay Bay in Las Vegas in the main event of an ESPN Top Rank card was postponed on Wednesday because Crawford suffered an injured right hand in a recent sparring session, Top Rank promoter Bob Arum told ESPN. He said the injury is not serious and the fight will be reschedule either for May 19 or in early June, also in Las Vegas.