Haaland is currently on holiday as Norway failed to qualify for the World Cup in Qatar.
Friends told The Sun that Haaland is “smitten” with the 18-year-old who he’s been dating for months.
The pair have mutual friends after growing up together in Bryne and both played for the local football side. Haaland was spotted with in Marbella where he owns a villa.
Haaland, who has scored 18 goals in 13 games for City, had previously said his footballs were his “girlfriends”. He said at the time;
“I sleep with the five balls for each hat-trick I have scored. I lie in bed and I feel good with them.”
Isabel has previously been spotted watching Haaland play while in the stands with his family, when he was still with Borussia Dortmund.
A source told the English publication;
“It seems to be pretty serious. Isabel has travelled to Germany and England to see Erling and now she’s been with him in Marbella.
“Isabel is well known for her beauty in Bryne. They’ve always known each other.”
The source also said;
“Erling has the world at his feet — and women queuing up to be his partner.
“But he’s a very sensible lad and it makes perfect sense he’s with a girl from his home town who he’s known for years.
“He needs to be able to trust the people in his life and just concentrate on football.”
Friends also said Isabel, who works part-time in a fashion store, deleted her social media accounts when she grew closer to Haaland.