"The burning of the jersey thing is getting ridiculous now! The man was traded. What do u not understand?" James said in the first of a string ot tweets, noting also that Thomas had shown tremendous heart when playing for the Celtics, suiting up for the playoffs in the wake of his sister Chyna's death in a car accident.
The tweet from one fan of a video showing him putting a match to his Thomas Celtics jersey prompted the response from James and others.
Other Boston fans, aware that it was Celtics management rather than Thomas who were responsible for the blockbuster trade that brought Cavs star Kyrie Irving to Boston in exchange for Thomas and Jae Crowder, tweeted pictures of their No. 4 Thomas jerseys with thank-notes to the popular player.
James has reason to be sensitive to the subject of jersey burning. When he opted to depart Cleveland for Miami in 2010 -- infamously saying he was taking his talents to South Beach -- myriad Cavs fans torched their James jerseys.
Unlike Thomas, James was a free agent at the time, and on Thursday he also defended Gordon Hayward, the former Utah star who signed with the Celtics as a free agent this year, to the dismay of Jazz fans.
James noted that Hayward "decided to do what’s best for him and family".
"(He) put in the work, got better, became an All-Star, etc!!" James tweeted. "If these guys weren't good, u guys would be the first to say 'get them up out of here.' Man beat it!
"When 'we' decide to do what (is) best for us it's 'cowardly,' 'traitor,' etc., but when it's on the other side it's 'business' huh? Ooh ok," James added. "Man do what u feel is best for your profession, love, family, happiness..."