The 37-year-old comic - who has previously battled addictions to drugs - has befriended the `Anger Management` actor, but pals are said to be worried about their bond because they don`t want the British star to be led astray.

A source said: "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.

"Russell has invited Charlie to join him at his yoga classes.

"But Hollywood is a small place and everyone is worried Charlie might lead Russell astray.

"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."

Despite warnings from his friends, Russell is always happy to hang out with Charlie - who was sacked from sitcom `Two and a Half Men` last year because of his erratic behaviour and wild partying - as he knows what it is like to go "off the rails".

The source added to the Daily Star newspaper: "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, 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."
sections: Celebrities