Cannon has departed the Blues following the end of his two-and-a-half year contract.
Arriving at Fratton Park from Rochdale for £150,000 in January 2019, the 25-year-old featured 79 times and scored three goals.
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Cannon’s now a free agent after Blues boss Danny Cowley opted not to activate a clause in his contract for an additional 12 months.
However, he’s seemingly not short of options.
As reported by The News, newly-promoted Bolton are one club who have been eyeing a move.
However, Cannon could make a move to the second tier after Pompey missed out on League One promotion again this term.
Preston have been credited as potential, which would see Cannon return closer to his native Greater Manchester.
Meanwhile, Hull claimed the League One crown this term and are plotting their return to the Championship.
Charlton will be planning another League One promotion bid after just missing out on the play-offs this time around.
Cannon bagged in the Blues’ 3-1 win at The Valley in February.