Arsene Wenger's hopes of signing Valencia defender Shkodran Mustafi were dealt a blow after the Spanish club said they will not entertain offers for the centre-back.
In a phone interview with The Straits Times on Sunday, Valencia manager Pako Ayestaran insisted that he will stand his ground against Arsenal's advances.
He intoned: "The club (have said) to any clubs that came to us for the player, or even to the player's agent, that we are not going to listen to any offers for him."
Asked again if the 24-year-old Mustafi, a World Cup winner with Germany in 2014, will leave during this transfer window, Ayestaran's emphatic answer was: "No."
But the British media have claimed that personal terms with the former Everton player have been agreed and Valencia, who are owned by Singaporean billionaire Peter Lim, will sanction the sale for a £50 million (S$88.6 million) transfer fee.
The asking price will shatter Arsenal's current record transfer fee of £41.5 million, paid to Real Madrid for Mustafi's international team-mate Mesut Ozil in 2013.
Arsenal transfer "fixer" Dick Law is reportedly in Spain trying to thrash out a deal.
Since arriving from Italian Serie A club Sampdoria in 2014, Mustafi has established himself as a first-choice centre-back. Even with defensive partner Nicolas Otamendi sold to Manchester City last season, the German's form never wavered although Valencia endured a poor campaign, finishing 12th in La Liga.
But Mustafi is not the only Valencia player coveted by a big club. Spanish sports daily Mundo Deportivo have reported that goalkeeper Diego Alves and striker Paco Alcacer are targeted by Barcelona.
Valencia sporting director Jesus Garcia Pitarch conceded that Alves could move on, but Alcacer will not be put in the shop window.
He said: "I've spoken with (Alcacer) and I've told him Valencia do not want to sell him.
"He's happy and looking forward to the start of La Liga and scoring goals. He has not told me he wants to leave the club. The club's posture is clear - Valencia don't want to sell Paco Alcacer."
In any case, Valencia's stance will not be music to Wenger's ears. With Arsenal's initial offer of £25 million way below the asking price, the Gunners' manager might need to come up with alternatives - fast.
The Frenchman is already under considerable pressure from the club's fan base for a lack of signings this transfer window, which closes on Aug 31.
That the Gunners have only one point from their opening two games - a defeat by Liverpool and a draw against champions Leicester City - hardly helps quell the frustration of the Emirates faithful.
The North London club have so far signed Switzerland midfielder Granit Xhaka, 23, and two youngsters, Japanese striker Takuma Asano, 21, and English defender Rob Holding, 20.
But fans are crying out for more. The Gunners' defence is depleted following long-term injuries to senior players Per Mertesacker and Gabriel Paulista, leaving Laurent Koscielny as their only recognised centre-back.