Hoffenheim sporting director Alexander Rosen has slammed Bayern Munich for their conduct in the signing of teenage forward Armindo Sieb.
The 17-year-old passed a medical with the Bundesliga champions on Thursday and will move on a free when the transfer window opens, although when that will be remains unclear with the German league suspended due to the coronavirus outbreak.
Rosen is, however, furious with the move, saying that Hoffenheim did not give permission for Sieb to have his medical and that Bayern behaved unscrupulously in pushing through the deal amid the current global situation.
Speaking on German television channel Sport1, Rosen said: "It was irritating that the player was called to Munich for a medical examination without coordination with us.
"Against the background of the current coronavirus crisis with all its limitations and challenges, I don't have the words for such behaviour."
Sport1 reported that Bayern informed Hoffenheim on Tuesday that the medical would take place two days later but Sieb's current club claim to have not given their approval.
They also say that Sieb had skipped a strength training session with Hoffenheim in order to have his medical and had only informed the club of this once he had travelled to Munich.
Sieb is one of German football's most promising young talents, with three goals in as many appearances for the national Under-17s side.
He initially joined RB Leipzig's academy at the age of 14 but moved to Hoffenheim in 2018 and made his debut for the club's Under-17 side at the age of 15, going on to score 10 goals in 25 appearances in his first youth-team season.
Sieb was proving even more dangerous at Under-17 level this season, with 10 strikes in 15 matches for Hoffenheim before the season was cut short by the coronavirus outbreak.
The signing of Sieb comes as Bayern look to continue forming their squad for next season with some of the best young talent from their Bundesliga rivals.
They have already agreed to sign goalkeeper Alexander Nubel from Schalke, although this has reportedly upset Bayern's current No.1, Manuel Neuer, and discussions with the German international over his future are ongoing.