Trump said he was thinking "very seriously" about granting clemency to Ali, adding that his administration is already "doing recommendations" on the late boxer.
A pardon for Ali would mark the second deceased boxer to be granted executive clemency under Trump. Last month, the president pardoned Jack Johnson, the first black heavyweight boxing champion, who was convicted of violating a law prohibiting the transport of women across state lines for "immoral" purposes. Johnson died in 1946.
Ali was convicted in 1967 on charges of draft evasion and was stripped of his heavyweight boxing title. A convert to Islam, the boxer cited his religious convictions for his refusal to serve in the U.S. Army.
The Supreme Court overturned Ali's conviction in 1971 — a fact that was pointed out in a statement from lawyer Ron Tweel, who has represented Ali and his family members since 1986.
"We appreciate President Trump's sentiment, but a pardon is unnecessary. The U.S. Supreme Court overturned the conviction of Muhammad Ali in a unanimous decision in 1971. There is no conviction from which a pardon is needed," Tweel said in a statement.
Trump told reporters on Friday that "there will be more pardons," before revealing his consideration of Ali as a potential candidate for clemency.
"I'm thinking about somebody that you all know very well, and he went through a lot," Trump said. "He was not very popular then, certainly his memory is very popular now. I'm thinking about Muhammad Ali."
Trump also said his administration is looking at "3,000 names" that could be eligible for executive clemency.
"That's what I want to do. We have 3,000 names, we are looking at them. Of the 3,000 names, many of those names really have been treated unfairly. This is a group of 3,000 we have assembled," Trump said.
The White House did not immediately respond to CNBC's request for comment.
Trump has received more than 2,800 petitions for pardons and commutations, according to the Justice Department. If Trump granted them all, he would still not surpass President Franklin Roosevelt's record of 3,307 pardons and commutations over nearly four terms in office.
On May 31, Trump pardoned conservative author and filmmaker Dinesh D'Souza, who pleaded guilty in 2014 to making an illegal campaign contribution.
He has also recently considered granting a pardon to celebrity chef and lifestyle mogul Martha Stewart, who served five months in prison after being convicted on charges related to a stock trade, as well as commuting the sentence of former Illinois Gov. Rod Blagojevich, who is in jail after being convicted of charges involving bribery and corruption.
After a meeting with Kim Kardashian West at the White House, Trump commuted the sentence of Alice Marie Johnson, who was imprisoned after being convicted of drug dealing charges.
Trump told reporters on Friday that he isn't just looking to pardon celebrities.
"I want to do people that are unfairly treated, like Alice," he said.
WATCH: Here's how presidential pardons work