And Perez's potential targets include Chilean global who was moments away from joining Manchester City on deadline day.
However, Sanchez seems determined to play under Pep Guardiola at Manchester City he will be able to sign a pre-contract with the Citizens in January.
Sanchez, who scored in the Gunners Europa League win against Cologne has made it clear he will not sign a new deal at Arsenal and was desperate to leave during the summer window.
City are very confident of finally landing a player they first went for in 2011 before he eventually opted for Barcelona, and will save themselves as much as £60million, the amount Arsenal agreed to sell him for before reneging when Thomas Lemar turned down a move to the Emirates.
Arsenal could feel it will be worth losing their talisman on a free next year, if he helps them get back into the Champions League this season.
Arsenal hero Merson: Ozil couldn't get a game at Chelsea
Asked whether the club would need his fighting spirit against Chelsea , Wenger said: 'Yes, but he played at Liverpool as well. Chelsea are coming off a huge start to their Champions League campaign midweek, smashing Qarabag 6-nil at home.
Karim Benzema's recent injury and the sale of Alvaro Morata has highlighted how the Champions League holders can be left short in attack.
Real Madrid, on the other hand, are looking to revamp their forward line and with Gareth Bale not living up to expectations, Los Blancos are expected to swoop in for Sanchez in January and make a bid of close to £50 million.
Real Madrid have also considered Bayern Munich's striker Robert Lewandowski and Borussia Dortmund forward Pierre-Emerick Aubameyang, but Sanchez is the preferred option as he could arrive for a cut-price deal in January or as a free agent next summer. Why not both in this weekend's big game?
With the score level at 1-1, Sanchez collected a long ball out wide before cutting inside and curling a shot into the top corner from outside the area.
Just select seven players from across the Saturday and Sunday Premier League fixtures for your chance to bag that tasty £5k prize.