Reports recently emerged that the pair were headed for the exit after being instructed to train away from the first team.
Speaking on Metro FM’s Sports Night Amplified with Andile Ncube, Barker shed light on the reasons behind the unexpected development.
"There is always a reason as to why one arrives to these kind of decisions. It's just not working for both club and player at this stage. Lesiba, at his age and with his quality, he wants to be playing a lot more than he is so that leads to frustration.
"As for Bradley, he started really well for us and then had a massive injury, sidelining him for close to a year, and he has since struggled a bit to regain his mojo and belief. Sometimes, a player and a coach sit down to have an honest conversation and the result of that could be a move to a different club to refresh the player and get his career back on track."
Asked why Nku and Mojela are being sidelined when they could keep fit for possible suitors, Barker played down what appears to be a harsh approach.
"I don't think it's anything bigger than what I've said on the situation. Sometimes its best to make those difficult decisions and we know both players will comfortably find clubs because there has already been a great interest in both so its not a question of having to keep them training."
Meanwhile, the coach, however, expects winger Devin Titus to sign a new contract with the club before his current one expires.