Top scorer John Marquis, the most likely to attract potential interest, will enter the final year of his current deal next season.
Andy Butler and James Coppinger penned new one-year extensions earlier this year.
Asked specifically if 21-goal Marquis would be rewarded with a new deal, Ferguson said this week: “It’s something we will deal with and it’s something that’s on the list.
“But I haven’t got any concerns about it at the moment.
“I don’t think the fans need to be concerned about us losing our best players.
“I haven’t got any worries about it.
“Don’t get me wrong, if someone comes in and blows you out of the water then...
“But certainly the conversations with the owners and Gavin Baldwin have all been very positive. We’re trying to keep the momentum going within the football club.
“If the fans are concerned, I would definitely be saying they don’t need to concern themselves.”
Marko Marosi, Aaron Taylor-Sinclair, Paul Keegan, Gary McSheffrey and Joe Pugh are out of contract this summer.
Ferguson has said a deal with Marosi is ‘virtually done’.
Ferguson, whose table topping side travel to bottom club Leyton Orient today, said: “I’ll probably speak to them before [we know what league we’re in next season].
“You can’t keep putting these things off forever.
“But obviously the season ends in May and not now and we have got bigger things to think about i.e. getting promoted. That’s the number one thing we need to get done.
“I’ve not had anyone knock on my door and say ‘I’m out of contract’.
“They know that once it’s done, or if we get it done, that getting promoted is the most important thing. The sooner the better for everyone, but we’re not counting our chickens. We’ve just got to concentrate on finishing this job off.”