Radebe, speaking on an ITV documentary, 'Leeds, Leeds, Leeds', said: "It got to a point where Mark realised the team needed him more and he needed to set an example, especially to the younger players at the club.
"The situation was difficult for us. We were right down at the bottom and we needed everybody together. You don't want players pulling in different directions.
"With 'Vidukes' we knew what quality we had. We knew, as well, the other side of him, when he was dragging his feet to the training ground, but we just accepted him.
"When you have someone turning up late for training and there are other players looking at you, you have to show them who is the boss.
"There were players on an awful lot of money at Leeds, but I think if you asked them they would admit they didn't give value for money.
"There was a malaise about the place and a defeatist attitude. I just couldn't shake it out of them. That was my job and unfortunately I couldn't do it."
Leeds hope sell Viduka, with Middlesbrough, Roma and Valencia all interested.
"The situation was difficult for us. We were right down at the bottom and we needed everybody together. You don't want players pulling in different directions.
"With 'Vidukes' we knew what quality we had. We knew, as well, the other side of him, when he was dragging his feet to the training ground, but we just accepted him.
"When you have someone turning up late for training and there are other players looking at you, you have to show them who is the boss.
"There were players on an awful lot of money at Leeds, but I think if you asked them they would admit they didn't give value for money.
"There was a malaise about the place and a defeatist attitude. I just couldn't shake it out of them. That was my job and unfortunately I couldn't do it."
Leeds hope sell Viduka, with Middlesbrough, Roma and Valencia all interested.