Glazer effigy burned at Old Trafford VIDEO: Gunning For United FA CUP ANGER WARNING Police have warned Manchester United fans who try to disrupt today's FA Cup Final against Arsenal in Cardiff: "We're ready for you." There are fears they might use the occasion to protest against the club's takeover by US sports tycoon Malcolm Glazer. But South Wales Police say the threat has merely added "spice" to the day - and they are prepared. Chief Superintendent Bob Evans said there would be no action against supporters who expressed their feelings by wearing black armbands. But immediate steps would be taken against fans who demonstrate inside the Millennium Stadium. He said: "Provided it is peaceful and outside the stadium that is fine. But we will not tolerate any sign of demonstration inside the stadium." More than 70,000 football fans are heading for the Welsh capital for the traditional climax to the English football calendar. Manchester United captain Roy Keane predicts the match, which kicks off at 3pm, could be a classic. He said: "I know sometimes FA Cup Finals can be a bit of an anti-climax. But I think this game will be explosive." United fans, and their Arsenal counterparts, will be kept well apart and plain clothes officers will mingle with the crowds in case of trouble.