Moreno also said the outfielder's contract contains language protecting the team against a relapse by Hamilton, apparently contradicting his previous statements. The players' association later issued a statement denying Moreno's claims.
Moreno spoke briefly to reporters on the field at Angel Stadium before the club's home opener against Kansas City on Friday night.
When asked whether Hamilton definitely would play again for Los Angeles, Moreno replied: "I will not say that.''
Moreno's comments are the latest development in an uncomfortable divide between the Angels and Hamilton, a five-time All-Star who hasn't come close to justifying his $125 million contract in his first two seasons.
Hamilton isn't with the team while undergoing rehabilitation on his surgically repaired shoulder, and he isn't expected to be ready to play again until May.
Moreno also claimed the Angels have language in Hamilton's contract protecting them against a relapse by the troubled outfielder. He said the team was exploring whether to use that protection, although he wasn't specific.
The MLBPA responded swiftly with a statement that it "emphatically denies'' Moreno's assertion that he had "requested and received the approval of the union" to put such language in a contract.
"To the contrary, the collectively bargained provisions of the [Joint Drug Agreement] and the Basic Agreement supersede all other player contract provisions and explicitly prevent clubs from exactly the type of action Mr. Moreno alluded to,'' the statement read.
Hamilton, who turns 34 next month, has three years and $83 million left on his deal with the Angels. The 2010 American League MVP has been largely ineffective in two injury-marred seasons in Orange County, managing just 31 homers and 123 RBIs.
Major League Baseball will not discipline Hamilton for his self-reported relapse after a ruling last week by an arbitrator appointed under MLB's joint drug program with the players' association. The Angels reacted angrily to the decision, with president John Carpino saying the ruling "defies logic.''
The Angels could have saved millions if Hamilton had been suspended, but the free-spending Moreno insists he isn't trying to pinch pennies two years after making the decision to spend nine figures on a 30-something slugger with a well-documented history of substance abuse.
"It's not about money," Moreno said. "Nothing about money."
Although Hamilton is swinging at pitches again following his surgery in February, he isn't expected to be ready to play for several weeks.
Angels manager Mike Scioscia has been noncommittal about Hamilton's return to the club. Hamilton never attended spring training with the Angels in Arizona, staying in Texas for shoulder rehab, and Scioscia has refused to say whether Hamilton will even visit with the Angels when they are in Houston next weekend.