The former ‘24’ star – who starred with the troubled actor in ‘The Three Musketeers’ and ‘Young Guns’ – admits he is worried about his friend’s recent erratic behavior and sympathies with Charlie’s father Martin Sheen, who was recently quizzed on his son’s troubles.

Kiefer – who has a 23-year-old daughter Sarah from his marriage to Camelia Kath – said: "A British interviewer asked him, 'I'm sorry to bother you about this, it must be a difficult time with everything your son is going through, how do you feel?' He as a father said, 'You have to love more.' And as a father, that really touched me. And so with regards to Charlie, I mean he's one of those cats that always seem to land on his feet and I wish him the best.

"I care a lot about him. And obviously, like a lot of people you get worried, but it's not something I know a whole lot about."

Despite his comments, Kiefer, 44, claimed he didn’t know much about Charlie’s recent antics – including being fired from ‘Two and a Half Men’ following a tirade against the program’s creator Chuck Lorre, losing custody of his two-year-old twin sons Bob and Max and moving two girlfriends into his home – because he doesn’t have a computer.

Speaking on ‘The View’, he said: "I haven't watched a whole lot of it. I'm the last person I know without a computer and I'm not into all of that stuff yet. I know Charlie as a really funny, talented, loyal, fiercely loyal guy. And clearly people are concerned about him and worried about him."