West Brom are to investigate crowd disturbances during Chelsea’s title-clinching 1-0 win at The Hawthorns on Friday, after nine fans were arrested.
Some Baggies supporters ignored a warning not to sell tickets in the home section to opposing fans.
Crowd trouble occurred after Michy Batshuayi’s late winner.
West Brom chief executive Martin Goodman said any supporters “who could be traced selling on tickets to visiting supporters faced sanctions”.
He added: “Naturally it is a matter of great disappointment for all at Albion and our thousands of genuine fans that a tiny minority would put profit before backing their team.
“We will also co-operate fully with police to help identify anyone clearly guilty of disorder offences during the disturbance.”