Sylla has been missing from Hartlepool since the end of last season after being left out of John Askey’s squad for the final two games of the campaign.
The midfielder, who signed a one-year deal for Hartlepool last summer, had a clause in his contract which allowed the club to take up the option of extending his stay by an additional year – something the club were keen to do.
But Sylla, with the club struggling to avoid relegation, was against the extension being triggered which resulted in a difference of opinion between the player and the club.
Sylla was one of the players accused as being 'selfish' by manager Askey after Hartlepool’s relegation back to the National League was confirmed.
“If people don’t want to play then I would prefer them just to say they don’t want to play,” Askey revealed to The Mail in April.
“I’ve met some of the most selfish individuals I’ve ever met in football. That’s why we’re in the position we’re in, because there’s some people who just think about themselves.
“I hope he gets what he deserves. He thinks he deserves a lot, so we’ll see.
“The very first time it happened, I’ve never come across it before,” Askey added to The Mail.
"For somebody to do that in the position the football club is in was out of order.
“He missed the Grimsby game and I thought everything had blown over as such and we’d just leave it then until the end of the season, but it didn’t.
“Sometimes it just comes down to that individual and you can’t control an individual if they do things like that.
“I’ve not come across it before and I’ve been in football a long time but I’ve never come across somebody doing that in the situation we were in."
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Askey’s frustration with Sylla was compounded when the Frenchman did not return to the club this summer ahead of pre-season.
Hartlepool reported back for several weeks of training before their opening friendly with Middlesbrough in mid-July where Askey provided an update on the absent 29-year-old.
"“Mo Sylla, we’ve not seen since the end of the season. It is what it is,” said Askey.
"We saw last season what he’s about, so while he doesn’t turn up then we don’t have to pay him, so that works out quite well.”
The Hartlepool boss was keen to draw a line under the saga ahead of the start of the season and now things have been concluded once and for all with the club receiving an undisclosed fee for the midfielder who heads north of the border to Dens Park.
A club statement read: “We thank Mo for his efforts at Hartlepool and wish him the best of luck in his future.”