The Scotland internationalist's career on Wearside appeared to be over when he was suspended by the club for going online to mock Sunderland's 1-0 defeat at home to Fulham on the opening day of the season.
Bardsley, who is recovering from a serious ankle injury, took to Instagram to post: "Great opening day. Hahahhahaha hahahhaha!!!"
After more than a fortnight exiled from the training ground, Bardsley this week said: "I would like to apologise to the club and supporters for my comments made on social media. I understand how they may have been interpreted and it was a serious error of judgment."
The apology was accepted and, in what was good news for future Scotland squads, the full-back is now expected to return to the Sunderland fold in the coming months.
Bardsley has endured a fractious relationship with the outspoken Di Canio since the Italian's arrival at the Stadium of Light in March.
He was publicly criticised by the manager after he was photographed at a casino in May with £50 notes spread over his torso. That led to the player being forced to train with the club's under- 21s during the summer.
Di Canio, meanwhile, has admitted he is delighted that the Scotland manager Gordon Strachan has resisted the temptation to hand Steven Fletcher an international recall.
The striker, who damaged ankle ligaments in March's defeat to Wales at Hampden, made a scoring return for the Black Cats in their defeat to Crystal Palace last weekend.
Fletcher was not named in Scotland's squad for the World Cup qualifying double-header with Belgium and Macedonia. The national team manager decided against drafting him in, especially since the Scots are out of the running in Group A.
Di Canio said: "The first thing you worry about when players are away is, of course, injuries. Fletcher himself has just returned from a long spell out with an injury he picked up on international duty.
"And so, as a coach, that is always something on your mind. But you are also a little concerned about players' fitness, too, because often when players are away on international duty they do not do a great amount of fitness work.
"That does not matter so much when it is later in the season and players are already very fit but at the start of the season you can still be working on players."
While Bardsley has made the cut for the upcoming Barclay's Premier League season, fellow Scotland internationalist Alan Hutton was left out of Aston Villa's 25. The former Hibernian and Rangers player Stephen Dobbie suffering the same fate at Crystal Palace.