McGhee has already lost two highly-rated youngsters to injury. Midfielder Steven Reid will be out for four weeks and striker Richard Sadlier for two months, leaving McGhee desperate to bolster his squad.
If the club could get a reasonable price for Cahill, who signed a three-and-a-half-year contract last season, McGhee is likely to get a significant proportion of the transfer fee and would look to bring in two or three new faces.
The Scot said: "We have found ourselves in difficult circumstances and I am having to look at short-term transfers and bringing the youngsters through. I am working hard with the chairman to see if there is any other way to improve the squad."
