Barton is due back in England today after an altercation with a 15-year-old that resulted in Dunne's injury in a Bangkok hotel bar. On Monday, when the squad return from the Far East and an investigation into the incident is completed, Barton could be placed on the transfer list.
Pearce reacted swiftly after speaking with the two players, several witnesses to the incident at the city's Radisson hotel and the club's chairman, John Wardle. He said: "Joey Barton is at the centre of the investigation. The players were given some time off after a squad meal last night. Richard Dunne was present but his behaviour was exemplary.
"If all the events that have been fed back to me are true, I'm very disappointed in Joey's behaviour. I always put my trust in players. That's the nature of things. I think any time anyone lets you down ... you're disappointed. I treat my players, hopefully, like adults and grown men until such time where they betray my trust."
Trouble erupted at 2am local time yesterday when a young Everton supporter attacked Barton in the bar of the hotel where City are staying during their participation in the FA Premier League Asia Trophy. The 22-year-old, who was released by Everton as a teenager, was abused and kicked by the supporter as he sat with Dunne. He responded by slapping his aggressor across the face.
Dunne acted as a peacemaker but Barton rounded on the Republic of Ireland international and bit him on the finger. The defender spun away and took out his frustration on a door, suffering the foot injury that has left Pearce facing the loss of three influential players in less than a week.
Neither Dunne or Barton were guilty of breaking a curfew as they were not due to play in the club's second game of the tour, against Everton at the Rajamangala Stadium today, and had been given permission to continue socialising after the meal at a restaurant. The pair chose to remain at the team hotel. They have since resolved their differences over the incident, although the repercussions are not over for Barton.
The man responsible for disciplinary procedures at City, the deputy chairman, Bryan Bodek, is on holiday in the United States. But he has been engaged in the investigation and will finalise the punishment next week.
City's head of communications, Paul Tyrrell, said: "Our inquiries here in Thailand are continuing. We have interviewed a number of people who witnessed the incident and will continue the investigation."
Barton's Thai adventure will cost him a minimum of two weeks' wages - and his City career if Pearce and club officials decide he is a liability they cannot afford.
In December the former England Under-21 international was fined six weeks' wages - two of which were suspended for a year - for stubbing a lit cigar into the face of the former reserve Jamie Tandy during the club's Christmas party.Reuse content