Following several discipline issues, Mhango has found himself on the sidelines despite starring at this year's Afcon finals in Cameroon.
Phiri has now advised the 29-year-old to leave Pirates to save his career.
"This situation is bad and of concerning for us," Phiri tells KickOff.
"Maybe the best solution will be for Gabadinho to leave Pirates because right now it doesn't help that he is not playing. How is he going to improve when he is not playing?
"It looks like the situation is so bad that the best thing to do for him is to leave," retired footballer Gerald Phiri Snr, father to former PSL star Gerald Phiri Jnr tells KickOff.
Mhango's situation at Pirates has sparked transfer rumours with links even to Tanzania.
"It will be a good move for him for the sake of playing though I also feel it will still be good for him to stay in South Africa and join another club.
"As coaches, we think differently about players and maybe the authorities at Pirates feel otherwise about him. So maybe he can move to another team in South Africa will be better than staying at Pirates.
"I don’t know if the coaches at Pirates have taken time to sit down with him and discuss the issues at hand and what the solution would be. If there is a problem, can they reconcile?
"I don’t know if that is possible but what I know is that we all make mistakes and if Gaba made a mistake somewhere somehow, I feel coaches should act like parents. If the boy misbehaved, they should have sat him down and found a way forward already instead of keeping the situation in suspense.
"I have spoken to Gaba. He is a human being and maybe he is hiding some of the information but what he says is that he has no problem with the coaches, so I don’t know where all of what is being said is coming from.
"I think the best way is to iron the problems at hand. He has been accused of indiscipline and what has been done about it in trying to find a solution. People make mistakes everywhere," says Phiri Snr.