The former Two and a Half Men star has struggled with addiction throughout much of his career, and was once hospitalised in 1998 after overdosing on cocaine.
In the midst of his troubles, Sheen's family and friends sat the actor down in a bid to persuade him to sign up for treatment, but the 46 year old refused - until he received a call from his former The Rookie co-star Eastwood.
During an appearance on sports TV show CenterStage, which airs in the U.S. on Friday night (06Jul12), he says, "There's a phone call at the very end (of the intervention), and it's Clint Eastwood. And he says, 'Come on, kid, you know, you're tougher than this, just go fix yourself, get back in the game.'
"And I was like, 'Alright, Clint.' How do you say no to Dirty Harry, you know? So I went (into rehab)... It helped at the time."