The Republic of Ireland international was one of the stars of the Latics' run to FA Cup glory last year and it was thought that he would be one of those departing the DW Stadium following their relegation.
While he still remains part of Coyle's squad, the manager knows that interest could well be ramped up in McCarthy and others as the end of the transfer window draws nearer.
"Do we expect phone calls? Absolutely because that's the nature of the window," said Coyle.
"Some will be people chasing, others will be genuine enquiries, and then from that there might be some sort of bids.
"As it is there hasn't been any as of yet but you never say never in this game."
McCarthy has been linked with Everton, where he would be reunited with former Latics boss Roberto Martinez, and Newcastle in recent weeks.
Any bid could come if the Toffees offload Manchester United target Marouane Fellaini or the Magpies part with want-away Frenchman Yohan Cabaye. And Coyle has braced himself for the usual flurry of activity that the end of the window brings.
He added: "As much as we'd like to be knowing in advance we're prepared for any eventuality.
"But there's no bids as we sit here for any of our players."