Charlie Sheen was late to work at “Two and a Half Men” yesterday, a source told Access Hollywood.

But it was for a good reason; the star was attending an AA meeting the source said.

Access Hollywood can also confirm that Sheen passed a drug test this week, ordered by the CBS show.

In related Sheen news, on Thursday, a judge in Colorado denied a request from Sheen’s attorney to allow the actor to appear by phone at a February 8 hearing over allegations he threatened wife Brooke Mueller with a knife on Christmas, the Associated Press reported.

The judge ruled Sheen must appear at the hearing next month.

As previously reported on AccessHollywood.com, Sheen, whose real name is Carlos Estevez, was arrested on Christmas Day after he allegedly threatened Mueller.

“My husband had me… with um, with a knife and I’m in fear for my life and he threatened me,” a woman, who identified herself as “Brooke,” said in the 911 call made on December 25.

A source told Access Hollywood on Monday, that the couple was in Aspen originally for a 10-day alcohol detox when they got into the fight.

According to an affidavit released by police, Sheen and Mueller began arguing in the early hours of Christmas Day – at around 3:30 AM, the Associated Press reported.

Mueller reportedly told Sheen she wanted a divorce and said she would get custody of their twin boys, according to the affidavit.

Sheen “became very upset with this threat (of divorce) because of prior experiences,” the affidavit noted.

Sheen, however, denied to police that he choked or threatened his wife with a knife. He reportedly admitted to authorities that the couple is having problems in their marriage and he claimed Mueller abuses alcohol, the AP reported.

Attorneys for both parties have asked a judge to lift a restraining order against the “Two and a Half Men” star, which forbids the actor from contacting his wife, in hopes the two can reconcile. However, Colorado prosecutors have requested the order remain in place. They did not give a reason for their request.