McCall insists he has not had any serious discussions with McFadden, who has been training with his former club after leaving Sunderland, despite mounting speculation the 29-year-old is about to sign a deal with the club where he launched his career.
But, amid what McCall termed the "euphoria" surrounding a possible return, he admits he will now speak to him after the Clydesdale Bank Premier League clash against Dundee United.
McCall said: "The latest on James is that he has been in training again this morning (Monday) and is going to come back tomorrow.
"Hand on my heart, as I keep reiterating, I have not spoken to James.
"The only thing I have said to James in the last four or five days is `give me 20 press-ups' because he keeps doing the wrong drills.
"I'm fully focused on tomorrow's (Tuesday's) game. But obviously with everyone discussing it now, things will have to come to a head and I'll have to speak to James, but it certainly won't be before Tuesday night's game.
"In that time, James might have moved on and got fixed up with a club.
"The arrangement was for him to come in and keep his fitness up, which he has been doing. But I will have to discuss matters, which will be on Wednesday."