The 26-year-old played 80 minutes of last night's 4-1 reserve-team victory over Middlesbrough after completing his six-match Football Association ban.

He could now return to senior action at the Stadium if Light on Saturday if manager Joe Kinnear decides he is ready, and he knows he has many questions to answer.

Barton told the Evening Chronicle: "Because of my past misdemeanours, it has been tough for me.

"The season starts here for me and hopefully, it is a case of onwards and upwards.

"It's the first game I have played, really. It is a starting point, but I have trained hard.

"The aim is to turn in performances for the fans. I want to do it for everybody connected with the club; players, fans and staff, everybody I have let down in the past.

"I want to go on to start paying back my transfer fee, which I don't think I did at any stage last year."

Barton, a £5.8million signing from Manchester City, was hit with the ban, a further six matches of which was suspended for two years, after admitting an FA charge of violent conduct against former City team-mate Ousmane Dabo following an incident that also earned him a fourth-month suspended jail sentence for assault.

However, his darkest moment came when he was sent to prison for six months following another incident in Liverpool city centre in December last year.

Barton, who pleaded guilty to charges of assault and affray, served 74 days and has made only one appearance as a substitute for Newcastle since his release.

However, Kevin Keegan, who replaced Sam Allardyce as manager in January, stood by the player, even resisting attempts to offload him on the final day of the summer transfer window.

Keegan resigned the day before the personal hearing Barton had requested in front of the FA over the Dabo charge, but the midfielder knows the debt he owes him.

He said: "Kevin, as everybody knows, put his neck on the line for me.

"He stuck by me, and I am eternally grateful to him for that.

"A lot of other people at the club stuck by me too, and they know who they are.

"Hopefully, I can go on and do a job for this football club."

Barton's most recent absence from the team has coincided with the club's descent into turmoil off the pitch, and interim boss Kinnear knows he needs every player he can muster to continue what is starting to resemble a mini-revival.

But the midfielder's combustible nature means he will not be an automatic choice for the game at the Stadium of Light, even though he is desperate to play.

Barton said: "I am ready for the Sunderland game. I know it is a derby and I am aware of how passionate the fans are about local derbies.

"I am more concerned mainly about getting my body right so I can be part of the squad.

"I haven't thought about the game too much. But in the coming days, the adrenalin will start running and the derby build-up kicks in."