The 37-year-old actor's friends are apprehensive about his friendship with Sheen as they fear he may lead Brand astray, reported Femalefirst.
"Russell has invited Charlie to join him at his yoga classes but everyone is worried Charlie might lead Russell astray," a source said.
Despite warnings from his friends, the "Get him to the greeks" star is happy to hang out with Sheen, who is renowned for his unbridled lifestyle.
"Russell's friends are panicking as Charlie keeps calling him, chasing him to meet up. Russell is too kind to say no, he thinks Charlie just needs a friend, but Charlie is a notorious bad boy and will definitely be a bad influence on him," the source added.