Mario Balotelli's agent Mino Raiola has revealed that the striker will not be leaving Anfield this summer.
Graham Dorrans has signed a two-year deal with Norwich City following a successful loan spell with the club.
The former Real Madrid winger was a high-profile signing for the Royals last summer but he did not live up to expectations, making just 17 appearances and scoring twice.
The 27-year-old Dutchman is currently training with Reading's Under-21 squad and has been told by manager Nigel Adkins he can leave the club.
Drenthe wore the number 10 jersey last season but that has been left vacant after Reading revealed their squad numbers on Monday morning.
Hal Robson-Kanu has taken the number nine shirt following Adam Le Fondre's move to Cardiff, while Jem Karacan will wear 21 because of his admiration of Italy midfielder Andrea Pirlo.