"He's been incredibly professional, always, but especially in times of personal crisis," Jon Cryer, Sheen's co-star on the hit comedy, tells PEOPLE. "He is solid as a rock [and] today was no different. ... It's a very funny episode so it went well. Thankfully a good script can get everybody through awkward moments."
Which is not to say Sheen isn't feeling the strain. "He was in his usual good humor on read-through day but obviously with the weight of something hanging on him a bit," Cryer adds.
Cryer, who says he reacted with "total shock" when he read about the arrest on the Internet on Christmas Day, stands behind Sheen. "He's been a good friend to me and it's painful," he says. "I love them both and they're a lovely couple.... I don't see that side of him. To me, he's been a great, loyal friend and a lovely guy to work with. He's a guy who dotes on his kids as much as any other father."
Of particular disappointment is Sheen's apparent alcohol relapse. "I know Charlie was immensely proud of his years of sobriety and I think that is the hardest thing they're both dealing with right now," says Cryer. "I know it was very important to him and I'm sure that's one of the saddest aspects for him."
Two and a Half Men's creator and executive producer Chuck Lorre insists any off-camera issues have never made their way onto the set.
"In seven years and one hundred and fifty-two episodes, Charlie has never been anything other than a total pro. No entourage, no star trips, just a professional actor doing his job," Lorre tells PEOPLE. "Apart from a few sick days and some babies being born, he hasn't missed a day of work. Beyond that he's been a good friend and colleague who's always fun to work with."