After coming close to joining Reading in January, the centre-back’s hopes of moving to England have been boosted with Black Cats boss Martin O’Neill contemplating a possible deal
The 23-year-old close to joining fellow Premier League side Reading in January before the move collapsed.
However, he has been handed another opportunity to join an English side and, despite picking up a knee injury in a friendly behind closed doors, Black Cats boss O’Neill is still evaluating whether to push through a deal for the centre-back.
He told reporters: “He played a little game the other day, but he had a swollen knee before he came here and he had to come off in the game.
“That will stop him training for a week at most. And then he'll be going away to play during the international break so we'll monitor him during that game.
“But I haven't seen enough of him yet to make a decision on him.”
Sunzu, who currently plays for Congo side TP Mazembe, will he hoping to impress in his country's upcoming World Cup qualifier.