Atleti rebuffed Arsenal's initial €25-million bid earlier in July and insist the Ghanaian won't be sold unless his €50-million release clause is met, Aarons and Romano add.
Partey, 27, has yet to sign a new long-term contract with the La Liga side. That fact has apparently boosted Arsenal's hopes of landing the central midfielder, but they are reportedly unwilling to pay his full release clause this summer.
Atletico manager Diego Simeone is reportedly eager to keep Partey, who joined the club in 2013 and has since developed into a core member of Simeone's XI; Partey made 35 league appearances this past season.
The relationship between Guendouzi and Arsenal, meanwhile, has apparently soured in recent weeks. The 21-year-old Frenchman didn't appear in any of the club's final 10 Premier League games after being involved in a post-match scuffle following a contentious June loss to Brighton & Hove Albion.
Reports suggested in the wake of that incident that Guendouzi would be happy to leave the Emirates this summer, with Mikel Arteta refusing to guarantee Guendouzi would be at the club next season.