Arsenal would consider selling Gabriel Magalhaes if an upgrade can be found, according to the Daily Mail.
Real Madrid want the 25-year-old as they need a cover for long-term injury absentee Eder Militao, while Saudi Pro League clubs are also monitoring his situation.
Gabriel was left out of the Arsenal starting line-up for their Premier League games against Nottingham Forest and Crystal Palace.
Gunners manager Mikel Arteta opted to play Ben White and William Saliba at centre-back for both matches, with the Brazilian seemingly out of favour.
Nevertheless, the indications are that Gabriel is most likely to stay, but there remains a small chance that Arsenal would consider letting him leave if they could find a replacement they believe is an improvement on the former Lille star.
The defender recently received his first call-up to the Brazil national team for the 2026 FIFA World Cup qualification matches against Bolivia and Peru next month, and while a move to Saudi could jeopardise his chances of finally establishing himself as a regular for country following several snubs, falling completely out of the starting XI at Arsenal could see him miss out on subsequent call-ups.
As a result, Gabriel could be open to joining Madrid if he is guaranteed a starting berth.
He started all 38 Premier League games last term and missing out on the first two line-ups this season could be worrying for him.
It appears the North London club will not hesitate to sanction a sale if an upgrade can be landed, with Bayer Leverkusen centre-back Edmond Tapsoba reportedly one of the players that are keeping tabs on.
Despite being a solid defender, White and Saliba are better centre-back options for Arsenal right now, and Gabriel may need to wait until Arteta decides to play White at right-back again before he gets a chance to start for the team.