That list includes Luciano Becchio, Neil Kilkenny, Bradley Johnson, Richard Naylor and Patrick Kisnorbo.
Davide Somma, Andrew Hughes and Shane Higgs will also become free agents next summer if United fail to agree or decide not to offer them new terms.
Discussions with the likes of Becchio were suspended during the transfer window to allow Leeds to concentrate on acquiring new players, but Grayson is keen to avoid the scenario which saw out-of-contract Jermaine Beckford depart Elland Road for nothing in May.
Grayson said: "The window's just shut but I'm sure it's on the agenda for (chief executive) Shaun Harvey to speak to their representatives."
Asked if the situation was a concern, Grayson said: "We'll try to keep the players but if they feel they're going to move on to bigger and better things by leaving on a free transfer then we can't do much about that - apart from offer deals which we think is their value.
"Players are within their rights to turn any offers down and walk out at the end of their contracts. In the summer we brought in one or two players who were on free transfers and that's what the Bosman ruling has done."