Kevin Keegan will make a personal plea to the Football Association when Joey Barton faces the governing body's disciplinary chiefs next month.
The 25-year-old is set to appear before the FA on September 5 after admitting a charge of violent conduct towards former Manchester City team-mate Ousmane Dabo.
The England midfielder received a four-month suspended sentence for assaulting Dabo and has spent 74 days in jail after being sentenced to six months' imprisonment for assault and affray for a separate incident.
Now Keegan has pledged to attend the hearing and claims Barton should be given another chance.
He said: 'I will appear personally at the hearing if required. Definitely.
'I supported him at court - so why am I not going to do it at the FA?
'For me it is the same thing. If you support someone you support them.
'If you believe they have turned a corner you believe they have turned a corner.
'If you believe that then what is wrong with saying it? So I will just support him 100%.
'I know a lot of people don't agree with me. I have had lots of letters and I have seen all the postbags.
'It is for me to make that decision on Barton and I have made what I think is the right decision.'