Wayne Rooney had over 22,000 followers on Twitter.
Manchester United Football Club has posted a message on its website explaining that its players do not belong to online social networks.
It advises users to treat any profiles in the names of its players with "extreme scepticism".
The club says this is because of the high numbers of people impersonating team members online.
There are many accounts across social network sites which claim to be in the name of high profile footballers.
"We don't want to stop players doing what they like within reason in their spare time," a Manchester United spokesperson told BBC News.
"But we do advise our players - especially the young lads - to be careful."
Manchester United players Wayne Rooney, Ryan Giggs and Darren Fletcher are believed to have had genuine accounts on Twitter, which are now closed.
"It wouldn't have been us who stopped them," said the spokesperson.
Digital communications expert Louis Halpern said he believes Manchester United is attempting to control the leaking of sensitive information.
However banning players from using Twitter would be "draconian" he said.
"People respond most passionately to other people online, and Twitter provides a huge opportunity for teams to really tap into their fan-base support," said Mr Halpern.
Footballers and Twitter do not always mix well.
Last year, Sunderland striker Darren Bent caused controversy after using the service to rant about the transfer negotiations with Tottenham, his former club.