French forward Christopher Nkunku returned on a loan deal Tuesday to RB Leipzig where he had the most prolific seasons of his career. Leipzig said the 28-year-old Nkunku joined on a season-long deal with an option to sign him permanently from AC Milan.

Nkunku scored 70 goals in 172 games in an initial four-year spell at Leipzig through 2023 that earned him a call-up to France's squad for the 2022 World Cup. He was injured in training before the tournament and replaced by Randal Kolo Muani. The most recent of Nkunku's 18 games for France came in World Cup qualifiers last November.

A two-season spell at Chelsea started with a serious knee injury and ended with winner's medals in the 2025 Club World Cup and the 2025 Conference League. He joined Milan in 2025 from Chelsea on a deal worth in the region of €40 million, but was deemed surplus to requirements under new coach Ruben Amorim. Nkunku scored just seven goals in Serie A last season for Milan.

Leipzig have money to invest for new coach Martín Demichelis since transferring teenage winger Yan Diomande to Real Madrid for an initial fee of €125 million. Nkunku becomes Leipzig's fifth arrival of the summer window, following Maxime Estève, Rocco Reitz, Ota Yamamoto and Ørjan Nyland.