Barton has been told he can leave the club on a free transfer in light of his ongoing Twitter criticisms of the Magpies hierarchy, despite the fact he has another year remaining on his contract.
After initially announcing via his Twitter feed he was "off to training", the midfielder then remarked shortly after: "Made to train alone today, how predictable........."
Barton even took to quoting George Orwell just before that when he wrote: "In times of universal deceit, telling the truth will be a revolutionary act".