Sunderland boss Martin O'Neill has confirmed he is running the rule over defender Stoppila Sunzu.
It will take a significant fee to prise Stoppila Sunzu away from Congolese outfit TP Mazembe, claims the club's owner.
Stoppila Sunzu's agent has called on TP Mazembe to allow the player to seal his proposed move to Reading.
Sky Sports understands Stoppila Sunzu's move to Reading has stalled over doubts about his situation at TP Mazembe.
Zambia defender Stoppila Sunzu claims he is poised to join Reading, with a transfer in the process of being finalised.
Sky Sports understands Reading are preparing an offer for Zambia defender Stopilla Sunzu after impressing on trial.