Russell Brand invites Charlie Sheen to join yoga

London: Comedian Russell Brand has invited Charlie Sheen to join his yoga classes and the former`s friends are concerned that Sheen could be a bad influence on him.

"Russell and Charlie have been spending an increased amount of time together as they`ve been named by (TV network) FX as the stars for their summer schedule so have done a lot of promotional work together," a website has quoted a source as saying.

Brand has previously battled addictions to drugs and has befriended Sheen who is known for being in news for wrong reasons.

"Russell is a strong guy, he won`t just fall off the wagon, but he`s single after his split from Katy Perry and on the look-out for women - and Charlie`s legendary parties are always packed full of beautiful women, the source added.

"Russell is too kind to say no, he thinks Charlie just needs a friend, someone who`ll look out for him. Russell was once in the same situation, off the rails and lonely. But Charlie is a notorious bad boy and will definitely be a bad influence on him," the source said.