It's understood the Trotters hold interest in the midfielder as they prepare for a League One return.
Arriving from Rochdale for £150,000 in January 2019, he scored three goals in 79 appearances for Pompey.
However, with Danny Cowley plotting a major rebuild and wanting to freshen the squad up ahead of a renewed promotion push, Cannon was released.
The decision left sections of supporters surprised, with the 25-year-old being one of the standout performers when the Blues topped the table during the first half of the season
It’s likely Cannon won't be short of admirers as a free agent this summer as he seeks his next challenge.
And it's understood that Bolton are one side who are potential suitors.
The newly-promoted Trotters are preparing for life back in the third tier after achieving immediate promotion from League Two.
Ian Evatt's outfit stormed up the standings in the second half of the 2020-21 campaign, going from flirting with relegation to finishing third and missing out on the title by three points.
As a result, Bolton have plenty of momentum behind them and Evatt will be hoping for back-to-back promotion bids.
The Bolton News reports there are 18 players out of contract in total.
That means Evatt will have some big calls to make as he plots the Trotters’ pathway back to the Championship.
A switch to Bolton would mean a move back to his Greater Manchester home for Cannon.