With Arsenal and Chelsea among clubs following his progress, Sesko will be clear to leave for a set price this season.
Writing on X, Sky Deutschland's Florin Plettenberg said: "Until now, there had only been talk of a verbal agreement, but Benjamin Sesko has a formally fixed release clause in his contract until 2029.
"This clause can be activated starting this summer. It is tied to various parameters – such as games played, goals, and assists – and increases regularly.
"Currently, the clause stands at around €70m for the 21-y/o top striker, but by the end of the season, it is expected to reach approximately €80m (£66m).
"All top English clubs have expressed interest, including Manchester United, Tottenham, and Arsenal. The only club not involved in the race is Manchester City."