"Jens ended up in a situation that we couldn't deny him. He got a fantastic offer, he's going to a league where the world's top players are," says Pogon's sports manager Dariusz Adamczuk to the club's website.
Gustafsson joined Pogon before the 2023-2024 season and has led the team in a total of 87 matches.
On the website, the club thanks Gustafsson for his efforts and wishes him good luck.
Gustafsson was one of the final candidates to become the Swedish national team coach, but the choice fell on Danish Jon Dahl Tomasson instead.
Gustafsson has been head coach at Halmstads BK, assistant coach at AIK, manager at IFK Norrköping, and national team coach for the U21 team, as well as coached Hajduk Split in Croatia.
It's not official which club in Saudi Arabia the Swede is going to.