Toney has not played for Brentford so far this season, missing both of their opening Premier League games against Liverpool and Crystal Palace.
The England striker has been linked with Chelsea in recent weeks but talks look to have broken down as the Saudi club swoop in for his services.
Toney would be one of the most high-profile players to move to Saudi Arabia and would join the likes of Sadio Mane, Cristiano Ronaldo, Karim Benzema and Neymar in a league that is growing in quality.
He was part of Gareth Southgate's England squad at Euro 2024 but struggled to get minutes on the pitch ahead of Aston Villa’s Ollie Watkins and Bayern Munich’s Harry Kane.
The striker has been left out of interim England manager Lee Carsley's squad for September's Nations League games after not playing any minutes so far this season.
He has scored 72 goals in 141 games for Brentford and is one of the most prolific strikers the Premier League has seen in years but now wants a move away from the club.