The Mean Girls star has had a tough few years following a string of legal woes, and the former Two and a Half Men actor allegedly handed over a $100,000 (£62,500) loan to Lohan to help her settle her tax debts.
Sheen reveals he is willing Lohan, who was last week (ends24Mar13) ordered to serve 90 days in a lock-down rehabilitation centre and stay away from drugs, to overcome her personal issues because he is sure she can make a career comeback.
He tells ETOnline.com, "There is a reason that I root for (Lohan), because we fell in love with this little girl that was just an absolute genius and had this great light about her and that's still there. You can't extinguish that. I root for her because when you're that talented it just doesn't go away. Sometimes your appetites get in the way."
The 26 year old filmed scenes for Sheen's Tv sitcom Anger Management this week (begs25Mar13), and the actor is hopeful his assistance is helping the actress: "I think she seems a lot more focused now than she was five, six months ago."
Lohan was handed the rehab order after striking a late plea deal in relation to charges she lied to police following a California car crash last year (12).