Ramos did not seem interested in the large salary offer from Al-Ittihad, he preferred Sevilla as a club at the start of his professional career. Ramos still has the opportunity to play in the top league even though he is 37 years old. Sevilla is also one of the clubs competing in the UCL this season.
Sergio Ramos is known for making records with his attitude and red cards. I could imagine being carded from Saudi Arabia altogether if he play there 
As a free agent, he didn't receive an offer from Inter Miami, a Turkish team was looking for him too and offered €11m a year but he refused. He didn't care also about Al-Ittihad offer of €20m a year and preferred to join Sevilla which only can afford €1m which he accepted. Normally after medical visit he will be a Sevilla defender again after 18 years from his departure there.