Sheen hit headlines in 2011 when his feud with the sitcom's creator Chuck Lorre went public, and the actor's increasingly bizarre behaviour eventually led to him being fired from the hit TV show.
Cryer was left in the middle of the melee, and had planned to back Sheen by releasing a letter of support, but he axed the move after his former colleague hurled a particularly nasty insult at him.
In an interview with U.S. newswoman Meredith Vieira on her talk show on Tuesday (14Apr15), Cryer revealed, "The day he got fired, my publicist said, 'Well, do you want to put out a public statement because you guys were sort of close.'
"I was in the middle of writing the statement, you know, 'It's been an honour to work with Charlie all these years', and then my publicist said, 'Oh wait - it's just come over the wire. He's just called you a traitor, a turncoat and a troll', and I was like, 'Okay! Let's put a pin in that statement of support!'"
Cryer went on to insist Sheen can be a good friend if he tries, adding, "He's capable of being a great guy - he just has to make that decision."