Nigeria, July 25 -- Newcastle United are keeping a close eye on the events around RB Leipzig striker Benjamin Sesko as a potential successor to Alexander Isak should the Swedish striker opt to depart this summer.

Having three years left on his contract, Isak has shown an interest in investigating other possibilities this transfer window. Although he has not formally requested a transfer, talks of a contract extension at St. James' Park have so far fallen through. The club values the player at roughly £150 million and repeatedly states he is not for sale; hence it maintains a hard bargaining position.

Newcastle are nevertheless getting ready for any conceivable result. Already taking action, the club seeks to learn the demands for a...