In 2010, Cleveland Cavaliers owner Dan Gilbert penned a scathing letter in which he eviscerated LeBron James for leaving his hometown team in favor of the Miami Heat. Four years later, the letter remains a major reason why James has yet to decide if he will play for the Cavaliers or the Heat next season.

A source familiar with the situation told ESPN’s Chris Broussard that James still isn’t over Gilbert’s disparaging comments. “If it wasn’t for that letter, this would’ve been done a while ago,” the source said.

In an infamous 2010 television event called “The Decision,” James announced that he’d leave the Cavaliers to sign a new contract with the Heat. Soon after, Gilbert wrote a letter in which he referred to James’ actions as a “cowardly betrayal.”

“[James’ deal with Miami] was announced with a several day, narcissistic, self-promotional build-up culminating with a national TV special of his “decision” unlike anything ever “witnessed” in the history of sports and probably in the history of entertainment,” the letter said.

It’s unclear if James and Gilbert have ever discussed the letter’s content. However, Gilbert has never issued a public apology, ESPN notes.

In the days after James opted out of his contract with the Heat, Rich Paul, his agent, reportedly encouraged the Cavaliers to spare nothing in their pursuit of the four-time MVP. To that end, the Cavaliers completed a three-team with the Brooklyn Nets and the Boston Celtics on Thursday, clearing over $20 million in salary cap space – money which will be used to offer James a max contract.

Furthermore, the Cavaliers seemed aware that Gilbert’s letter may still be a source of friction between him and James. As negotiations progressed, the franchise removed all traces of the letter from its website.

Sources in James’ camp revealed on Thursday that he plans to speak with his family before deciding to sign with the Heat or Cavaliers. However, there are reports that the announcement will be made on Friday, before James flies to Brazil to attend the World Cup final.