The Premier League champions have been heavily linked with Agger as Roberto Mancini grows increasingly impatient at the lack of new faces this summer.
City rate the Denmark defender in the £18million bracket.
However, Rodgers, whilst admitting he does not want to lose Agger, acknowledges that everyone is for sale if the price is right.
And in Agger's case, that price will be big.
"Every player has a price and top centre-halves are at a premium," said Rodgers.
"Thiago Silva has left AC Milan for PSG for £40million.
"He (Agger) is one of the leading players in European football, so it is going to be a big valuation.
"Is he a player I want to lose? No. He understands how I want to work and can play a real pivotal part in how I want to play.
"But I am a realist. If someone comes in with a massive bid and it is in the best interests of the club, whether it is Daniel or any other player, you have to look at it."
Rodgers' words merely underline the brutal reality of life at Liverpool.
The club are heading towards a third successive season outside the Champions League, a tournament they won as recently as 2005.
And owner John Henry has made it clear he simply will not fund the kind of massive signings splashed out on during Kenny Dalglish's ill-fated 18 months in charge.
"The reality is we don't have the money that was here," he said.
"I don't have a bucket load of money to go and get in a load of players.
"We have to be strategic."
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Rodgers confirmed talks with Cardiff are on-going over Craig Bellamy, who wishes to move back to south Wales for the final stages of his career.
"I would think he would be leaving," said the Liverpool boss.
Somewhat more confusing is the status of Andy Carroll, who has been the subject of interest from West Ham but is only keen on returning to former club Newcastle.
"Between now and the end of the window there are going to be players feeling a little bit unsure and insecure," said Rodgers.
"There is a new manager and more players to come in.
"But Andy has been terrific. He knows exactly where he stands.
"I understand Andy wants to play games but he has to fight for their position. There are not many clubs you could go to and be a guaranteed starter.
"The point is when that transfer window shuts everyone has to be totally focussed about being here.
"There can be no regrets about not going if you had the chance to on loan or not."
Thus far, Rodgers has been unable to strengthen and refused to confirm the status of his obvious interest in Swansea midfielder Joe Allen.
It is all rather unsettling ahead of Thursday night's Europa League return with Belarus outfit FC Gomel.
Liverpool head into the Anfield encounter a goal ahead, which at least means that the Northern Irishman should be able to enjoy his first home game in charge.
"Anfield is so inspiring," he said.
"You see the flags and scarves and there is so much tradition and heritage at the place.
"That is the draw. That is why I came here.
"It is a club that can really go forward.
"There will be no prouder man than myself tomorrow night [Thursday]."