Napoli failed to complete the signing of Roberto Soriano from Sampdoria in time for his transfer to go through on deadline day, after beating Serie A rivals AC Milan to the midfielder.
An agreement had been reached between the two clubs and the player late on Monday evening, but time ran out as Napoli drew up the contract and, according to Sky Sport Italia, they failed to meet the 11 p.m. deadline to send his contract to Lega Serie A officials for ratification.
The Italy under-21 international had been a target of the Rossoneri for much of the summer, but they were unable to agree a fee with the Genovese club.
After Napoli coach Maurizio Sarri complained about his lack of options in midfield, club president Aurelio De Laurentiis promised him a deadline-day signing, but he failed to deliver it in time as the doors to the negotiation room of a Milan hotel, where the Lega Serie A had set up office for the final day of the transfer window, were slammed shut.
The Azzurri were reportedly willing to pay €13 million for the 24-year-old, who was born in Darmstadt, Germany, with Camillo Zuniga joining Samp as part of the deal.
However, the deadline passed without Napoli managing to complete the necessary paperwork.