The left-back was dropped for Saturday's defeat to Sunderland after Allardyce revealed the player had been distracted by a bid from the midlanders.
And even though the Rovers boss is resigned to losing Warnock he insists the club will not budge from their valuation of the player.
With Manchester City set to pay a reported £24million for Everton centre-back Joleon Lescott Allardyce believes what they are asking for the former Liverpool player, who can also operate in midfield, is fair.
In July Portsmouth right-back Glen Johnson moved to Liverpool for £17million - although much of that was eaten up by cash Pompey still owed from the signing of striker Peter Crouch - while last January Wayne Bridge swapped Chelsea for Manchester City for £12million.
"I think we levy the value at this summer's market," said Allardyce, who has already played hard-ball with City over striker Roque Santa Cruz to secure an £18million transfer fee.
"You look at the overall players that have been bought - defenders particularly - and you put a valuation around what the market is suggesting it should be.
"I think that is a sensible thing to do. I spent many a year evaluating transfers in the old tribunal system as a League Managers' Association member.
"Our decisions were always based on the transfer value of players in that player's position over the last year or so and what club they were going from and to.
"We have had a look at that situation and we'll see where we go."
A growing injury list means Warnock has been included in the squad to travel to face Gillingham in a Carling Cup second-round tie on Tuesday night but he could yet be pulled out if Villa come in with an acceptable bid.
Allardyce believes that is likely to happen at some point before the close of the transfer window.
"There is no acceptable bid as yet from Aston Villa so he is still a Blackburn player and I need him to travel with the squad tomorrow - at the moment," added the Rovers boss.
"What happens in the next few days will go on what negotiations go on between John Williams (chairman) and Aston Villa.
"I think it is obvious he would like to move to a club of that size. I don't want to lose him but as much as I want to keep him it doesn't look like that is going to be the case."
Allardyce, who is not a fan of the transfer window, is concerned that the longer Villa take to come up with the cash the less chance he has of finding a suitable replacement.
"It is always the same, it's a crazy transfer window. There was nothing wrong with the old system we had," he said.
"Unfortunately we had to be brought into line with the rest of Europe but just because the rest of Europe were doing it it doesn't mean it was right.
"You have to bear in mind my position as it becomes sacking season when it doesn't go for you.
"It generally becomes sacking season because you can't have your best players available because of an extended injury list - which you can do nothing about until the January window."
Allardyce's injury list appears to be growing by the day with defenders Ryan Nelsen (knee) and Chris Samba (heel) and forward Franco Di Santo (hamstring) out of Tuesday night's tie against the League One side at Priestfield and striker Benni McCarthy doubtful with an ankle problem.
"We will have to go with what we have got and we haven't got a lot at the moment," said the manager, whose side have lost their opening two Premier League matches.
"It shows the value of a squad because at the moment we are down to the bare bones but the bottom line will be about the players' mental attitude.
"The players we select will all be good enough to beat a Gillingham side that have started well and are very organised.
"They (Gillingham) will play above themselves because they will want a Premier League scalp so the players have to get the mental attitude right and if they don't they will get embarrassed."
Blackburn 5/6, Draw 12/5, Gillingham 11/4