Dinamo Zagreb have told Arsenal if they want Marcelo Brozovic in January they must prepare a bid that will knock the the Croatian club off their feet.
The Gunners have reportedly deployed scouts to watch over Croatian international Brozovic this season while his agent, Miroslav Bicanic, revealed last month he would hold talks with the Premier League club over a possible offer.
More recently his Bicanic denied reports he was in talks with Inter over the player's possible £5m move to the San Siro.
With interest in the 22-year-old intensifying, Dinamo executive director Zdravko Mamic has warned Brozovic's suitors that only an irresistible offer will be enough to tempt them into doing business.
"We have no offers," Mamic told sportski.net. "If someone wants one of our key players it can only be with a memorable bid -- if they knock me off my feet.
"That is my principle. And the numbers appearing in the media do not interest us."
Arsenal are expected to invest in a holding midfielder during the January transfer window after failing to strengthen that area of the team in summer.
Brozovic, who primarily plays in a more attacking position but can be deployed in a more defensive role, signed a seven-year deal at Dinamo following his move from Lokomotiva in 2012. His rapid progress since has seen a number of Europe's elite linked with his signature.
In recent years, Gunners manager Arsene Wenger has been reluctant to reinforce his squad during the winter transfer market due to the difficulty in convincing clubs to sell, along with the prospect of exorbitant transfer fees.
But, given the club's worst ever start to a season since in 1982, Wenger is coming under increasing pressure to strengthen his side with a holding midfielder and a centre half top priorities in the new year.