Alexander Isak believes "not everyone has the whole picture" of his 125 million pound (US$169 million) record move to Liverpool after an acrimonious exit from Newcastle.

Isak played his first minutes of the season in Sweden's 2-0 World Cup qualifying defeat to Kosovo on Monday after failing to feature for Newcastle in their opening three games of the campaign before his transfer to Liverpool on September 1.

The 25-year-old made his desire to leave the Magpies public in a social media post last month, claiming that the club had broken promises.

Isak went from hero to villain in the eyes of the Newcastle support and was the target of offensive chants in the early weeks of the season.

He scored the decisive goal in March's League Cup final win over Liverpool that won Newcastle's first domestic trophy in 70 years.

"It's clear that not everyone has the whole picture, but that's something for another day," Isak told Swedish media.

"That's part of football. I can't control everything that is said or written but I'm glad I became a Liverpool player. That's what I wanted and I'm happy about that.

"There is a lot to discuss, and it can be discussed for a long time. It has been educational, and I'm happy with the final result. I'm happy and proud to be a Liverpool player."

Isak will train with his new Liverpool team-mates for the first time this week ahead of his expected debut away to Burnley on Sunday.

The defending champions have made a fast start without him as the only side to win all three Premier League matches of the new season so far. (AFP)