The 26-year-old turned up for the first day of pre-season training at the club's Darsley Park headquarters at 9.47am as he and his team-mates began preparations for the new campaign.
Barton was told to stay away after a stand-up row with then boss Shearer in the wake of his sending-off at Liverpool on May 3, an offence which ruled him out of the final three games of the Premier League season.
His future remains a matter of some speculation with the club certain to move on many of their high earners as they prepare for life in the Championship.
Five international players - Damien Duff, Sebastien Bassong, Jonas Gutierrez, Geremi and Xisco - have been given extra time because of their exertions with their countries since the end of last season, while Michael Owen, Mark Viduka, Claudio Cacapa, Peter Lovenkrands, David Edgar and Ignacio Gonzalez were all out of contract at midnight last night.