Commissioner Rob Manfred said a decision on discipline probably would come "shortly after" Opening Day.
"I think that we'll have something on Hamilton in relatively short order — probably has been a little slower just because he's not available to play," Manfred told SiriusXM on Wednesday.
Hamilton, recovering from shoulder surgery, was expected to be on the disabled list until May. However, he suffered a relapse in his battle with substance abuse and met with officials from Manfred's office on Feb. 25.
Time on the disabled list counts as time served on a suspension, according to baseball's drug policy.
Hamilton is scheduled to make $25 million this season. He is in the third year of a five-year, $125-million deal with the Angels.
If he is sent into a rehabilitation program, he would be owed his full salary for 30 days, then half his salary for the next 30 days — a total of $6.2 million. If he is suspended and not in treatment, he would not be paid. However, it is unclear whether the Angels would have to pay Hamilton at all if he previously entered a rehabilitation program that lasted at least 60 days.
Hamilton has a long history of drug and alcohol abuse, and has been suspended in the past.
The 33-year-old outfielder has 31 homers and 123 RBIs in two injury-interrupted seasons.