"Jeremy Lin is a good player but all the hype is because he's Asian. Black players do what he does every night and don't get the same praise," Mayweather wrote on his Twitter account on Monday afternoon.
Lin's agent, Roger Montgomery, didn't immediately respond to a text message sent by ESPNNewYork.com. Leonard Ellerbe, Mayweather's top adviser, didn't return a phone call from The Associated Press.
Mayweather, however, responded to the story later Monday via a series of tweets.
"Its OK for ESPN to give their opinion but I say something and everyone questions Floyd Mayweather," the boxer tweeted. "I'm speaking my mind on behalf of other NBA players. They are programmed to be politically correct and will be penalized if they speak up.
"Other countries get to support/cheer their athletes and everything is fine. As soon as I support Black American athletes, I get criticized."
Lin has become the talk of the NBA -- and the sports world at large -- for his unprecedented play over the last five games.
Lin is the first player in league history to have at least 20 points and seven assists in each of his four career starts. The Harvard grad has scored 109 points in his first four career starts, which is the most by any player since the NBA and ABA merged in 1976. In his last five games -- all Knicks wins -- the 23-year-old is averaging 26.8 points and 8 assists.
Lin, an Asian American, is the first American-born player of Taiwanese or Chinese descent to play in the NBA. Lin's parents emigrated from Taiwan in the 1970s. A grandmother remained in mainland China.
Lin was an end-of-the-bench player for New York (13-15) for most of the season. The Knicks sent Lin to the D-League for one game in January and he played just 22 minutes in his first month with the team. In his first opportunity to play extended minutes, Lin scored 25 points and had seven assists in a win over the New Jersey Nets.
Lin has led the Knicks to a season-high five straight wins. He went undrafted out of Harvard and was released by the Golden State Warriors and Houston Rockets in the preseason before being claimed off of waivers by the Knicks.
Mayweather has drawn attention for racially insensitive remarks in the past. Mayweather went on a profanity-filled racist and homophobic rant against Manny Pacquiao in September 2010. In a video posted on UStream, Mayweather told Pacquiao, a Filipino, to "make some sushi rolls and cook some rice." He also said "we're going to cook him with some cats and dogs."
Ian Begley is a regular contributor to ESPNNewYork.com. Information from ESPNNewYork.com's Michael Woods was used in this report.