Eredivisie giants Ajax were interested in loaning Hartman, who joined Burnley from Feyenoord last summer and hadn't played at all in December after initially being a starter.
The move failed, however, and after an intern from sports agency Forza Sports Group leaked information about the circumstances in which Hartman declined moving to Amsterdam, Hartman reacted to the turmoil in an Instagram story.
"Earlier this month, I told my agent and Forza that I'll be using the right to represent myself and that they won't have to work for me anymore," said Hartman. "Why? That is something between me and Forza.
"After I informed Forza of my decision, I informed Burnley that they shouldn't contact Forza anymore, but me instead."
A move to Ajax would've come as a shock after Hartman came through the Feyenoord academy and had played 83 games for the senior squad before leaving for Burnley last summer. Ajax and Feyenoord are bitter rivals, with only very few players having played for both clubs.
"During that same conversation (with Burnley), I indicated that I feel that my situation has changed (over) the past few weeks due to personal reasons. Recently, I heard that Ajax were interested in loaning me and that they had approached Burnley," Hartman continued.
"Burnley did not want to loan me out, and that is where the story ended."
The Forza Sports Group intern shared in a public Discord channel that Hartman pulled the plug himself after receiving threats at his, his family's, and Forza's addresses.
"Very shortly after I'd heard the news, the story ended up in the media, a lot was said about me, and I received a lot of unpleasant messages. Unfortunately, based on false information," Hartman said of Dutch reports on his supposed willingness to move to Ajax.
"Via this message, I would like to make clear that I will not move to Ajax and that I will give everything for Burnley as long as I'm here," Hartman emphasised.
"We are in a difficult period right now, so it seemed disrespectful to discuss a club other than Burnley. However, I think it's good to clear things up as I am the only person who knows what's going on."
Hartman has appeared in 15 Premier League games for Burnley, providing four assists along the way.
