Arsenal are reportedly concerned Real Madrid could hijack their deal to sign Real Sociedad and Spain star Martin Zubimendi this summer.
The Gunners have been heavily linked with a move for Zubimendi, who has a release clause of £51million.
Recent reports claimed Zubimendi could undergo an Arsenal medical with all payment structures claimed to have been agreed.
According to Spanish newspaper Marca, Real Madrid have now entered the race to sign Zubimendi.
The Spanish giants reportedly contacted Zubimendi's entourage to determine whether he had finalised a deal with Arsenal, which is camp are claimed to have denied.