Sheffield United have urged supporters with any information regarding a second coin-throwing incident in as many months to come forward.
The latest occurrence took place after the Blades' third penalty in the midweek League Cup Trophy tie against Notts County.
It follows on from an identical situation during September's League One clash with Colchester United.
South Yorkshire Police are investigating the latest incident, which involved a coin being thrown in the direction of the opposition goalkeeper.
United have now issued a plea for fans to come forward, with managing director Mal Brannigan adding in a statement: "Behaviour of this manner will not be tolerated and anyone found to have committed this offence will receive an automatic life ban from Bramall Lane.
"This sanction will be separate to any action South Yorkshire Police can impose. We are working closely with South Yorkshire Police to identify the individual or individuals who committed these mindless acts. The club has, in the past 12 months, installed and upgraded its CCTV network throughout Bramall Lane and in particular The Kennedy Kop Stand.
"The footage that comes from the cameras is very clear and was used to ban two individuals following unwanted behaviour last season. Bramall Lane has a very good reputation for being a safe environment to both watch and play football. The club will do its utmost to ensure this remains so."
Anyone with information has been asked to contact info@sufc.co.uk.
