Joey Barton's agent Willie McKay claimed the player's shock transfer request was not about money - but then stated if Manchester City had offered what they asked for the midfielder would have signed a new contract.
City opened contract talks with Barton only last week but were stunned by the 23-year-old's decision to ask for a transfer - which was immediately rejected last night.
Manager Stuart Pearce stood by the player last July when he was sent home from a pre-season tour of Thailand in disgrace after being involved in an altercation with a 15-year-old Everton fan at City's team hotel in Bangkok.
Barton was given another chance and responded with some impressive displays this season which led some to suggest that he might be handed an England call-up.
It also prompted City to begin negotiations on an improved contract, talks which appear to have now stalled.
'Joey had a conversation with Stuart Peace yesterday. It is not just all about money. It is about Joey Barton wants to go and where Manchester City want to go,' said McKay.
'If Manchester City had come back with the offer we had asked for, which in my opinion is below what Joey should be getting any way, then Joey would have signed the contract.
'It has not doubled his contract [money] and he asked for a transfer request. I think he is a little bit upset.'
McKay also accused City of taking advantage of Barton's long history with the club, which he joined as a schoolboy, and claimed if he had not been a rising star they would have dumped him after his off-the-field problems.
'I am appointed by Joey to do the best for Joey. It is not just Manchester City, other clubs take you for granted when you come through the ranks,' he added.
'During those difficult times, if he was not the player he was and was on the periphery of the team, a below-average player, in my opinion I don't think Manchester City would have stuck by him.'
McKay, however, said Barton would continue to give his all for the club during the remainder of his contract.
'He has got 15 months left on his contract and I can assure all Manchester City fans he will give 100% during that contract,' he told Radio Five Live.
Barton has attracted interest from several Premiership clubs - thought to include Arsenal, Birmingham, Charlton and Middlesbrough - and it remains to be seen if a move away from Eastlands unfolds before the January transfer window closes at midnight.
The Thailand incident was not the first controversial moment in Barton's career.
In December 2004 he stabbed a lit cigar into the eye of young team-mate Jamie Tandy during club's Christmas party and was fined six weeks' wages by City.
After the Thailand incident Barton stressed he was determined to 'make things up' to Pearce.
Barton's form suggested he was determined to make the most of City's backing and last month he played on despite learning his brother Michael had been found guilty of the racist killing of Anthony Walker and must serve 18 years in prison.