Sesko has caught the eye with his performances in Austrian football and is tipped to become the next promising player to depart Red Bull Salzburg for a bigger league.
The Austrians do not want to sell him, but they could soon be tested with big offers and the striker could push to go.
Manchester United are keen on taking Sesko to Old Trafford and have held meetings over a potential deal.
Chelsea are also looking to secure Sesko and spoke to the player’s agent in a meeting last week.
Sesko is now deciding what he wants to do this summer, amid Red Bull Salzburg hoping he will be happy to stay put for a further year.
The 19-year-old has already turned out for Red Bull Salzburg in the new season, scoring once and assisting once in two Austrian Bundesliga games.
Sesko also played and scored in an Austrian Cup win over minnows Fugen last month.
Another club are claimed to be in the race for him too, but it is unclear who they are at present.