Harris is out of contract this summer and Cardiff have been keen to keep him in Wales.
However, the Bluebirds have seen their proposal for a three-year deal rejected by the attacker, who now looks set to head elsewhere.
It is suggested Blackburn and Derby – the Rams have made an offer – are now on red alert and hoping to be Harris’ new home.
Blackburn asked about Harris in the January transfer window, but the fee quoted by Cardiff put them off.
Now the situation is different and the 24-year-old is set to end his association with Cardiff.
He clocked 35 appearances in the Championship for Cardiff over the course of last season and found the back of the net on three occasions.
Harris played in both Cardiff’s Championship meetings with Blackburn last season, giving the Ewood Park outfit an up close look at him.
