Celtic and Rangers can quash fears of mass gatherings on Sunday - by wielding the banhammer.Collins knows the ferocity of the fixture having taken part in derby matches between the two clubs during his playing days at Parkhead and later as Ronny Deila's assistant.He believes after the exuberant celebrations of Ibrox diehards toasting their Scottish Premiership win, there's a need for both teams to be stronger in their messaging to supporters.Managers John Kennedy and Steven Gerrard plus captains Scott Brown and James Tavernier have urged supporters to stay at home for the powderkeg clash to avoid a repeat in Glasgow's east end, the city centre or elsewhere.But Collins reckons that's not enough - and said the threat of a year-long ban from.