Since leaving Leeds, Gradel has twice been struck down by the same injury.
The latest injury, which occurred during Bournemouth’s game against Leicester, will rule him out for six months.
There is a suggestion that Gradel suffered his first knee injury in 2013 after falling out with his family.
He recovered from that injury and won the Africa Cup of Nations with the Ivory Coast.
That followed a thawing of relations with his family. Since then, Gradel’s career has gone from strength to strength - he scored 17 goals in Ligue 1 last season, earning a move to the Premier
However, Gradel then fell out with his sisters and uncles once again, and the result, it has been claimed, was the second knee ligament injury.
An anonymous source told The Sun: “Gradel’s family has been working spiritually against him.
“He had risen from the ashes as a result of reuniting with his family, and he told them he would never become estranged from them again.
“But Gradel must have been bewitched, as after he joined Bournemouth he turned his back once more.
“He clashed with elder sister Deborah and argued with uncles. He was oblivious to the poverty his sisters live in.”
Gradel is well regarded at Elland Road, having won the Yorkshire Evening Post’s Player of the Year award in 2010/11 as Leeds pushed for promotion.
He has been repeatedly linked with a move back to Leeds, but none has ever materialised.