The midfielder is one of 11 players whose deals expire at the end of the season.
Also among them are fellow regular starters Tom Naylor, Jack Whatmough, Ryan Williams and Craig MacGillivray, along with the rejuvenated Ben Close.
The club does hold the option of an additional 12 months with both Cannon and Close.
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However, the former Rochdale man admitted the Blues have yet to discuss exercising that clause nor table him fresh terms.
Cannon's trying not to think about his contract situation too much during Pompey’s League One promotion push.
But with little more than a month of the campaign remaining, the 25-year-old insists the Blues need to start negotiations immediately.
Cannon, who scored a stunning match-winner in the 1-0 victory at Wigan on Monday, told The News: ‘Nothing has been said. Listen, I'm just going game by game and trying to help the team.
‘If you keep on helping the team and doing well then you'll get rewarded if you are doing things right.
‘Nothing at all (has been said about taking the year option). I think they need to start talking to a couple of the boys who are out of contract, definitely.
‘I don't like it, but karma can come around. You need to look at the boys who are fully out of contract first because there are some really good players who are out of contract.
‘I know the club needs to know what is going on about fans returning etc, but it needs to get sorted now if they want to keep the players who are very good and out of contract. It needs to get sorted one way or another.
‘I've had nothing said to me. I don't know whether they are going to take the option or not.
‘People don't try to think about it too much but things have got to start to get sorted now.
‘We're into April and for the boys fully out of contract, for me even, we need to hear something.’
Jordy Hiwula, Charlie Daniels, Haji Mnoga, Duncan Turnbull and Bryn Morris are also out of contract in June.
Pompey also hold 12-month options on Mnoga and Turnbull, who has joined Las Vegas Lights on loan.
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