Liverpool had previously made a £110 million bid for Isak, but the club rejected it. Since then, there has been no progress in negotiations, and the transfer window is nearing its end. Waddle believes that Newcastle should have sold Isak a long time ago, citing the significant amount of money involved in a potential transfer.

"If I were Newcastle, I would sell Alexander Isak this week," Waddle said. "Isak's transfer value is in the hundreds of millions, and it's not worth keeping him in the reserves. If he were to leave for Liverpool, I think the club should accept a large sum of money, including add-ons, and move on from the situation."

The entire situation has been handled poorly, according to Waddle, who compared it to a amateur team's handling of a transfer. He believes that Isak or his agent has mishandled the situation, leading to the current impasse.

Isak has not played for Newcastle since May and is unlikely to feature for the team again. He was recently called up to the Swedish national team and issued a statement on social media, accusing Newcastle of breaking a promise to allow him to leave this summer.