League One's 'most valuable' players who clubs could sell now or risk losing for free in summer - including Derby, Barnsley, Reading and Peterborough aces: gallery

Pompey currently have eight senior permanent players on their books who could walk away for nothing upon the expiry of their existing contracts this summer.

Among them are Marlon Pack, Joe Morrrell, Sean Raggett and Joe Rafferty - who are regular starters for John Mousinho's current table-toppers. Meanwhile, Connor Ogilvie and Zak Swanson - two players out injured a present - are also now into the final six months of their agreements.

What Pompey, and all clubs really, generally do in such circumstances is wait and see how the future looks before making final calls on these individuals. What division will they be in, a player's performance over the closing stages of the season, the wages they'll likely be asking are among factors to be taken into consideration before a decision is made.

Alternatively, some clubs might make the call early and decide to cash in on their player in January in order to get some financial return on ther initial investment. Peterborough's Jonsson Clarke-Harris is a good example of this, with Posh preferring to sell the striker now before losing him for nothing in the summer.

No doubt, other League One teams find themselves in similar positions. especially if they have no option to extend a player's stay. So here's the 'most valuable' players currently plying their trade in League One - according to transfermarkt.com - who are out of contract in the summer and whom it might be worth cashing in on now, before they can walk away from their clubs for nothing in six months time.

Note: No Pompey player out of contract at the season's end made the most valuable list, according to transfermarkt.com. Also, clubs can claim compensation for any player under the age of 23 who has come through their youth ranks.