Angels general manager Jerry Dipoto said he disagrees with the ruling by an arbitrator appointed under MLB's joint drug program with the players' association. MLB said earlier Friday that it disagreed with the ruling.
Hamilton, a five-time All-Star and the 2010 AL MVP, has played poorly during the first two years of his five-year, $125 million contract with the Angels, who still owe him $83 million in salary over the next three years.
He is subject to the treatment program for prior violations involving cocaine stretching back a decade.
The Angels' public stance supporting punishment of Hamilton is the most visible evidence yet of the club's disenchantment with the high-priced outfielder, who has been injured for long stretches of two largely miserable seasons in Orange County.
"Do I agree with the decision that was made by the treatment board? Absolutely not," Dipoto said before the Angels' exhibition game against the Dodgers. "But that's not my decision to make."
In a statement, MLB said it will "seek to address deficiencies in the manner in which drugs of abuse are addressed under the program in the collective bargaining process."
Hamilton self-reported a new issue this year involving both cocaine and alcohol, a person familiar with the case said. The person spoke to The Associated Press on condition of anonymity because those details were not made public.
MLB said it took "the position that Hamilton violated his treatment program and is subject to discipline by the commissioner."
Baseball defines cocaine as a drug of abuse, which is covered by different rules than those for performance-enhancing drugs, such as steroids.
A four-person treatment board created by the joint drug program, which includes one lawyer and one medical representative each appointed by management and the players' association, deadlocked 2-2 on whether Hamilton's conduct was a violation of his treatment program and was subject to discipline. That created the need for an arbitrator to break the tie.
A person familiar with the process said the arbitrator was Roberta Golick, a former president of the National Academy of Arbitrators. That person spoke on condition of anonymity because her name was not announced.
A hearing was held before Golick, and Hamilton was represented by lawyers Jay Reisinger and Tina Miller. The arbitrator said only that Hamilton was not subject to discipline and did not give reasons for the decision, the first person familiar with the case said.
The Major League Baseball Players Association said in a statement that it will "respect the integrity of the negotiated joint drug agreement process and protocols, as well as any decisions that are the result of that process."
Hamilton, who turns 34 in May, won the AL MVP award with Texas during a six-year stretch as one of baseball's best all-around players for the Rangers and Cincinnati Reds. But his career headed downhill in his final season in Texas, and it has picked up speed with Los Angeles.
Hamilton has managed just 31 homers and 123 RBIs in two seasons with the Angels. He played in just 89 games because of injuries and struggled at the plate throughout last season, culminating in an 0-for-13 performance in the Angels' three-game loss to Kansas City in the AL Division Series.
After resting his ailing right shoulder throughout the off-season in the team's unsuccessful attempt to avoid surgery, Hamilton had surgery in February that will prevent him from playing until at least May. Hamilton never reported to spring training in Tempe, Arizona, instead pursuing his surgery rehabilitation at home in Houston with the Angels' blessing.
When asked how Hamilton might perceive the Angels' comments about the ruling, Dipoto pointed out that the Angels have been actively supportive of Hamilton ever since they signed him. Hamilton has had two "sober coaches" to monitor his behaviour, just as he did with the Rangers, and the Angels claim they have expended extensive resources to keep Hamilton safe.
"But we're not going to sugarcoat issues that exist with our team as we move forward," Dipoto said. "And to me, that's the important element not to forget here. We have a team to focus on. ... We have a responsibility to a group of guys down there that have committed to winning, and we're going to go out there and show our support for that group as well."
Dipoto said he hadn't spoken with Hamilton on Friday, but only with the outfielder's representatives.
Manager Mike Scioscia and his players have been outspoken in support of Hamilton, but the club also has removed his oversized photo from the outside of Angel Stadium for this season, taking him out of the group of six star players annually honoured. His locker in the clubhouse is temporarily occupied by new second baseman Johnny Giavotella during the weekend exhibition series.
"We're all thinking about Josh and praying for him," Angels third baseman David Freese said. "But when it comes time to play ball, we're worried about who's in this clubhouse. Not having a talent like Josh when he's rolling is huge, but there's a group of guys in here that are determined to get it done and win the division again."
Hamilton was the first pick in the 1999 amateur draft out of Athens Drive High School in Raleigh, North Carolina, but his surge through the minors was sidetracked by substance abuse beginning in 2001.
He barely played baseball for four years, but found stability off the field with sobriety counselling, a wife and a family that now includes four children.
A year after resuming his career in the minors, he ended up in 2007 with the Reds, getting a long standing ovation when he made his major league debut. He had 19 homers and 47 RBIs as a rookie, and Cincinnati traded him to Texas in the off-season.
He was an immediate hit with the Rangers, leading the league with 130 RBIs and earning a starting spot in the All-Star game in 2008. He won the AL batting title in 2010, and he was selected the AL Championship Series MVP while leading the Rangers to their first World Series appearance.
But even during his success, Hamilton had problems. He acknowledged a relapse in early 2009 after he was photographed getting drunk in a bar in Arizona, and he held a news conference in 2012 to apologize for another night of drinking.
After playing in a second World Series in 2011, Hamilton had a career-best 43 homers and 128 RBIs in 2012 despite injury problems and a late-season slide.
The Angels risked an enormous contract on Hamilton to add his left-handed bat behind Mike Trout and Albert Pujols, but Hamilton has provided only short stretches of the world-class hitting expected — and now he has become the distraction long feared by the contract's detractors.
"This is a disappointing moment, make no mistake," Dipoto said. "We'll move forward, we'll make the best of it, and we'll try to find and reach a conclusion that makes sense for all involved. That will happen when it happens. We're in no rush. Josh is going to start on the disabled list, and we'll take it day by day."
AP Sports Writer Greg Beacham contributed from Anaheim, California.