Cahill has spent the last three months on loan at Sheffield United and is keen not to lose the match-fitness and sharpness gained from regular first-team football.

However, any offers for Cahill, who was on the substitutes’ bench against Liverpool on Monday night, have not met Villa’s valuation of the player – believed to be around £4m.

O’Neill, who would prefer a permanent deal rather than for Cahill to again go out on loan, said: “I have given Alex (McLeish) permission to speak to Gary.

“A number of teams have not only enquired about Gary, but a number of clubs have put offers in – none of which have been acceptable to us or have been accepted by us.

“Birmingham City, I can confirm, have made an offer but I have not accepted any of the offers because they do not meet the valuation.

“I am not in a hurry to sell Gary but he doesn’t want his career to remain stagnant and I can’t guarantee him playing in our side immediately. But things can change.”

O’Neill added: “Gary’s situation is straightforward. Having spent the last three months out on loan at Sheffield United and having played well and regularly, he doesn’t want to lose that now and I can understand his predicament and his difficulty.

“Maybe he would like to go out on loan somewhere to the end of the season. Now that is something I will give some consideration to but it is not my utmost thought at the moment.

“If he doesn’t want to leave permanently and feels there is a chance here that’s fine. I am not going to shove anyone out of the door.

“But getting some sort of loan fee for someone at the end of the day is of no phenomenal benefit. That is exactly what I said to Alex and everybody else who has enquired about him.”