Luis Fabiano's agent Jose Fuentes has warned AC Milan that they must travel to Spain and raise their offer or risk losing out on the striker.
The Sevilla frontman is said to favour a move to the San Siro although negotiations have stalled after Milan offered just £12.5million.
The Spanish side are thought to value the 28-year-old at closer to £18million, meaning that the two clubs are still a long way off agreeing on a fee.
Rossoneri officials stated that the deal had come to 'a dead end' but Fuentes has called for the Italians to prove how much they want the Brazilian.
"We are waiting for Milan to take the first step and begin negotiations with Sevilla," Fuentes told Telelombardia.
"We cannot hang on for a week, because it will be easy for Luis Fabiano and Milan to reach an agreement on terms.
"Milan have got to fly to Seville, raise their offer and make a small sacrifice quickly to take him away. The player will cost £18million."
Milan fans are growing restless with the lack of transfer activity at their club especially following the sale of influential star Kaka to Real Madrid for £55million.
Despite the funds generated from the Kaka sale remaining untouched the Serie A giants still tried to land Fabiano for the cheaper price of £9million after speaking to the Rio and Stellar group who own a small percentage of the player's contract.
The move is said to have angered Sevilla but Milan general manager Adriano Galliani insists they were not going behind the Spanish club's back.
"It was a courtesy meeting, even if we explained that the only reference point for us in these negotiations are Sevilla.
"They are the only ones who can release the transfer."
Galliani increased doubts on the deal when he added that the Rossoneri may not look to increase their initial offer.
"Our offer remains the same: £12.5million. Sevilla do not agree and so for the moment we will wait and see what happens."
Meanwhile Milan boss Leonardo has secured his UEFA A second category coaching badge.
The Italian football federation had given him special dispensation due to the fact that he had played at the highest level in the 1994 World Cup for Brazil but the former midfielder decided to take the course anyway.