Swansea manager Brendan Rodgers has vowed to sell players in future who reach the last year of their contracts and do not wish to sign new deals.
Darren Pratley, Dories De Vries and Angel Rangel will be able to speak to prospective clubs in January as they are free to leave the Swans next summer.
The Swansea boss believes the Championship outfit missed an opportunity to maximise their capacity to bring money in last summer and is determined to avoid a similar situation in the future.
He told the South Wales Evening Post: "From next year, if people are going into the last year of their contracts and they are not going to sign, then as a football club we need to try to earn what we can.
"I think that's what you have to do from a business perspective.
"Thankfully, I have no worries about the attitude of any of the players who are in their last year now. But it's a situation I would prefer not to have.
"I think we missed the chance in the summer to maximise the capacity to bring money in.
"From the club's perspective and the player's perspective, you will not get so much from doing something in January."
On reported Newcastle, Celtic and Nottingham Forest target Pratley, who has suspended contract talks with the club, Rodgers added: "I think Darren will be one where we see it through until the end of the season and see where that takes us."