Boateng, Ricardo Rocha and Adel Taarabt have not been given squad numbers by Spurs head coach Juande Ramos and a short-term move to the Coca-Cola Championship is still an option now the transfer window has closed until January.

Birmingham co-owner David Sullivan described the deal as "still a possibility", and suggested the Germany Under-21 midfielder was close to being bought by another club at the start of the week.

"Another club were about to buy him for a pile of money, but then changed their mind," he said in the Birmingham Mail.

Boateng's wages were thought to be standing in the way of a return to Germany, where he established himself at Hertha Berlin before getting noticed by Comolli.

Comolli, as sporting director, has been scouting players for Spurs since 2005 but Ramos gave his assessment of the squad he inherited last season by allowing seven first-team players to leave.

Robbie Keane also left for Liverpool and Dimitar Berbatov for Manchester United, in deals that represented huge profits for the club.

In the case of Berbatov, however, former boss Martin Jol has previously suggested the Bulgaria striker was on his own radar while scoring goals at Bayer Leverkusen in the German league.

Jol also described Taarabt as having the ability to be the next David Ginola, although the midfielder has only made six substitute appearances under Ramos.

Centre-back Rocha has not played under Ramos, and the three will not be given squad numbers unless they are called up for first-team duty.