Benfica have warned those casting admiring glances in the direction of Joao Felix – with Manchester rivals United and City said to be among his suitors – that €100 million (£88m/$112m) will not be enough to do a deal.
The 19-year-old playmaker has emerged as one of the most sought-after talents in Europe.
His potential has been noted by leading sides across the continent and a scramble for his signature is expected to be sparked at some stage.
Portuguese champions Benfica will, however, not be parting with a prized asset for any less than they consider him to be worth.
They have a man who scored or assisted 31 goals in 2018-19 tied to a contract that includes a €120m (£106m/$134m) release clause and have informed those mulling over summer bids that they will not be moved from that asking price.
Benfica’s executive manager Domingos Soares de Oliveira has told TVI124: “The goal is to keep the squad. If someone hits 100 million for Felix, the intention is not to sell.
“100 million is a lot of money, there has never been a player sold for that amount in Portugal, but the goal is to win on the pitch and we will do everything in that direction.
“Today, if they do not meet 120 million, the player stays.”
Rather than readying themselves for the potential sale of Felix, Benfica are piecing together plans to keep him on their books.
The Portuguese champions have a deal in place that is due to run until 2023, but are already plotting fresh terms.
If they are able to reach a new agreement with Felix, then they will be able to increase his release clause and continue to fend off the mounting interest being shown from afar.
De Oliveira added: “I think the president still has the intention of reviewing, but on the other side there is the player, the entrepreneur, the family.
“What we have to do is to anticipate, looking at the potential of the player, are try to persuade the other party.
“There are talks and rumours, it is true that the biggest European clubs have interest, but no proposal has come to us.”