Newcastle United failed in a last-minute attempt to lure 18-year-old Moussa Sissako from PSG, despite agreeing a fee with the French side.
The centre-back has been told by manager Thomas Tuchel that he is not part of his first-team plans this season, as he would be competing with established defenders such as Thiago Silva, Presnel Kimpembe, Marquinhos and new arrival Abdou Diallo, who signed from Borussia Dortmund this summer.
This allowed Newcastle - as well as Brighton, who also agreed a deal with PSG - to swoop in for the Frenchman, with both sides confident that they could secure his signature entering the final day of the English transfer window.
According to RMC Sport journalist Loic Tanzi, however, personal terms could not be agreed between Sissako's representatives and the English clubs, who both offered four-year contracts to the highly-rated teenager.
Sissako is still able to leave his hometown club this summer though, with most other major European transfer windows still open for at least two weeks yet. Other than remaining in France, he could very well end up in Spain, Italy or Germany, with numerous clubs circling.
Similarly, Newcastle had agreed a deal for fellow PSG youth product Stanley Nsoki; the move failing through as a result of wage demands, with the left-back believing his value was higher than the offer extended to him.
Having lost Rafa Benitez in a move that angered Tyneside, Newcastle have brought in four first team players this summer, most notably Brazilian forward Joelinton from Hoffenheim in a £40m deal, and the £20m acquisition of winger Allan Saint-Maximin from Nice.
Additionally, Andy Carroll has returned to his boyhood club after eight and a half years elsewhere, singing a one-year deal on a free transfer, while Swedish international Emil Krafth was recruited at right-back.
Newcastle kick off their Premier League season on Sunday at home to Arsenal, as the Magpies aim to avoid relegation.