Forward Camilo Duran is the only addition to the Celtic squad ahead of the new campaign.
As well as McGregor, speculation also surrounds the futures of Daizen Maeda, Arne Engels and Reo Hatate.
Manager O’Neill was reported, external as saying that McGregor “hasn’t hinted to me he wants to leave”, but he conceded that “money is a big thing, particularly when you’re past 30”.
However, when asked how motivated he was after taking his major trophy count to 26 with last season’s double, the captain said: “That’s the job of a Celtic player, that you don’t get tired of winning.
“We have set ourselves an unbelievable standard over the last 14 or 15 years, being successful, winning numerous titles and trophies, and trying to push all the time in European football to be as good as we can be.
“And all that does is bring bigger expectations, a bigger target on your back, so you then have to work even harder to defend it.
“The players and the core group that have been here for a long time understand that and they have to drive that level.
“As a Celtic player you can never ever be bored of winning and trying to be the best that you can be, and trying to improve individually and collectively.”
