The 30-year-old has been one of the most prolific strikers in Germany over the past few seasons, scoring 60 goals in 96 games since joining Dortmund from Stuttgart in July 2024.
Guirassy had been linked with a potential move away, with several reports suggesting the likes of Real Madrid, Barcelona, Manchester City, Liverpool, Chelsea, Manchester United, and Arsenal would have been able to sign him for a fee of just €40m.
That clause has now expired, however, and Dortmund are increasingly confident that Guirassy will remain their player beyond the summer.
Turkish side Fenerbahce had been keen, but Sky Sports reporter Patrick Berger has said: "Serhou Guirassy actually rules it out for himself to move to Turkey now.
“At BVB, they have planned internally with Guirassy and without (Karim) Adeyemi; those were the two sale candidates.
“Therefore, I currently strongly assume that Guirassy will also play for BVB next season, unless something nevertheless happens."