Tottenham will insist on their valuation of Dimitar Berbatov being met before allowing the striker to leave White Hart Lane.
Berbatov missed Saturday's defeat to Sunderland after being deemed psychologically unfit and a threat to dressing-room harmony - and a repeat could see the Bulgaria captain feature in Clive Allen's reserve team.
Tottenham boss Juande Ramos is believed to be willing to see Berbatov feature with the reserves if they do not receive a suitable offer for the striker from Manchester United.
Spurs are understood to be looking for at least £30m for the 27-year-old - who has handed in a transfer request in pursuit of a move to Old Trafford - and they are waiting for a bid from United before the end of the transfer window.
Tottenham's next match is Sunday's Premier League trip to Chelsea, and they will hope Berbatov's future is resolved by then - whether he stays or the club receive funds for Ramos to spend before the following day's summer transfer deadline.
Ramos and Berbatov met last Sunday for more talks about the future of the £10.9m signing from Bayer Leverkusen, who has spent two years with Tottenham.
Tottenham have put the ball in United's court, and they must decide whether there is mileage left in their pursuit of the player.
Historically, United do not find themselves backed into a corner during transfer negotiations - their interest in Michael Essien and Arjen Robben fell away when the price was not right. Rather than being held to ransom, they have been willing to miss out on a player.
They also tend to do their business earlier in the summer rather than leaving it until close to the deadline to complete deals for players.
Striking a deal with Spurs would also probably see the Premier League complaint against United dropped, after they were effectively accused of tapping-up Berbatov.
Spurs would ideally want to bring in a striker before allowing Berbatov to leave, particularly as Darren Bent is their only available out-and-out striker at the moment.
Radamel Falcao from River Plate is the latest name to be linked with a move to White Hart Lane, with Wigan's Emile Heskey also reported over the weekend as a potential target.