Club captain Jay DeMerit's deal also runs out in the summer, though the USA international has openly expressed that he does not wish to open negotiations until after this year's World Cup in South Africa.
"Everyone is on their own individual merits in terms of having discussions with them (contracts)," Mackay told the club's offical website.
"I think you have to do it like that. Everyone is in a different situation and in a different point in their career and will have different attractions and options.
"There is no sweeping statement where I would say there will be any across-the-board way we will treat everyone."