Chelsea have vowed to ban for life any Blues fans who racially abused John Obi Mikel.
The Stamford Bridge club urged police to investigate after the Nigerian was on the receiving end of at least two race-based abusive tweets following a costly error he made in Wednesday’s Champions League draw with Juventus.
Mikel insisted he closed down the account before the messages came to light.
He said: “I was riled by the tweets but that’s not why. It wasn’t about that.
“I just closed it because I’m not really into Twitter. I really did not like being on it and I wanted to stop ever since I started.”
But club officials promised to take “the strongest possible action” against any supporter found by the police inquiry to have sent the tweets to the midfielder, which would mean life bans from the Bridge.
Blues boss Roberto Di Matteo spoke with Mikel on Friday to ensure he was in the right frame of mind to play their weekend game against Stoke.
And Di Matteo attacked the anonymous trolls who went after a man who played a huge part in last May’s FA Cup and Champions League triumphs.
Di Matteo said: “Social media, because it’s anonymous, is a dangerous vehicle to express yourself.
“Fans have the right to express their opinions and their feelings, but in the right way. Football has always been a sport that has united not divided people and that is the message to to all supporters.
“We condemn any kind of discrimination or comments or some sort of racist abuse, absolutely.”
Arsenal manager Arsene Wenger has warned football faces an “endless fight” against racism after Lazio were charged over ‘monkey’ hoots aimed at Tottenham striker Jermain Defoe on Thursday night.
UEFA, whose president Michel Platini was at White Hart Lane, opened a disciplinary case against the Italian club’s fans over the racial abuse in the Europa League on Thursday night.
The case will be heard on October 18 and Wenger said: “How we improve things is by being absolutely resilient against stupidity.
“It looks like it will be an endless fight, but we must fight against it.”