Doncaster have made forward Dany N'Guessan their sixth summer signing.
Tottenham have confirmed that Romanian defender Vlad Chiriches has completed a move to Napoli.
The 16-year-old Scotland U21 international has put pen to paper on the new deal after making his first-team debut as a substitute in the 5-0 home win over Daugava Riga in the Europa League earlier this month.
Dons manager Derek McInnes told the club’s official website: "I'm really pleased to fix Scott up on a long-term deal.
“It's vital that we nurture the players who have come through our youth development system and they all know that, irrespective of their age, if they're performing at the required level, they will get a chance to be part of a successful Aberdeen side."