Cahill has been tracked by most of the Premier League's top clubs over the past 12 months, with Arsenal and Chelsea thought most likely to make a move in the January transfer window.
Bolton have yet to receive any calls to enquire about the central defender's availability, but it seems a matter of when and not if he leaves the Reebok Stadium.
"I saw speculation about Gary Cahill yesterday and I can sit here very comfortably knowing we have had no dialogue about him or any of our players, and long may that continue," he said. "I think it is important we keep this group together and try and add one or two.
"I don't fear bids for Gary or any other player. Could it happen? Yes, because they are quality players.
"But when they move for £20 million, £25 million or £30 million, which is what it takes to buy them, they would be better moving in the summer as they need a pre-season as if they move in January they are under too much pressure to make an immediate impact."
Coyle also moved to distance himself with speculation over a loan move for Arsenal striker Carlos Vela.
"Carlos Vela is an outstanding player," Coyle added. "I think Arsene said at the weekend he could go on loan and people have looked and put two and two together.
"We have a good relationship with Arsenal, obviously with Jack Wilshere last year and hopefully we played a small part in his development, and there is no doubting Carlos Vela is a wonderful player."