Newcastle manager Alan Pardew has suggested that Joey Barton's career at St James' Park may not be over.
The 28-year-old was made available on a free transfer this week after contract negotiations broke down leading him to air his frustrations on Twitter.
"I've never closed the door on anyone and I'm not closing the door on Joey," said Pardew.
"He trained with the development team today and, who knows, he may train with the first team soon."
On Tuesday, Barton claimed that he had trained alone and also revealed on Twitter he had been fined two weeks' wages. Neither the club or Barton revealed what the fine was for.
"Joey is a great player and you want great players in your team," added Pardew, whose side face Arsenal at home in the opening league match of the season on 13 August.
"It's very important as a football club that you are all pulling in the same direction - at this moment of time Joey is not pulling in the same direction.
"That's not to say that can't change in a short period of time."
Pardew believes that the use of Twitter has caused problems at his club and that Newcastle are now following Manchester United's guidelines on players' use of the social networking site.
"Maybe if it wasn't for Twitter and this instant media it may have got resolved on Monday morning with me and Joey in my office," he added.
"The problem with Twitter - we need to get a hold of this.
"I spoke with Sir Alex Ferguson today and he's had this problem with Twitter before.
"We're now following the guide that Sir Alex has said they have done [at Manchester United].
"I'm not against those sites, and I don't think many managers in the Premier League are, but they have to be careful not to mention the football club."