AS says Arsenal were said to have identified Isak as a target before the Euros as his stock continues to rise.
And Chelsea have now joined the Gunners in the race for the 21-year-old, who has a release clause of £60million (€70m).
The Blues are on the lookout for a new striker and want to sign Erling Haaland, the man who effectively ended Isak's hopes of making the grade at Borussia Dortmund.
Yet Chelsea are well aware that signing the Norwegian could prove difficult given his value and therefore, alternatives are being identified.
Isak is a lethal finisher, has pace to burn and displayed his nimble footwork against the Spanish defence.