Ku claimed Blackburn were in attendance to monitor his performance against the European outfit but admitted he was unsure as to whether he would be heading to the north-west.
"I know that negotiations are progressing. I think that it is 50-50," he said.
"I know that someone from Blackburn watched the game against Latvia and I know that my agent and Blackburn start serious negotiations today."
Ku also hopes his performances during the training camp and his spectacular strike in the 4-2 friendly defeat against Zambia will have boosted his chances of making Korea's World Cup squad.
"I learned so much during the training camp and am so thankful to get that opportunity," he added.
"When I was with the national team I did my best to earn a place for South Africa. I don't know whether I will or not but I have no regrets."