Tottenham chairman Daniel Levy is prepared to increase the asking price to £40m for defender Toby Alderweireld when his release clause expires on Friday.
Alderweireld currently has a £25m release clause in his contract, which must be paid in no more than three instalments and within a two year period, but that will end on 26 July, allowing Levy to hold out for more money for the Belgian centre back from any interested parties.
The Telegraph claims that Levy will raise Alderweireld's price tag to £40m following the 26 July deadline.
Despite his low release clause, there has been precious little concrete interest in the 30-year-old Belgian. Roma were said to be interested, but cannot afford the player's wages, meaning they are yet to make an official offer to Tottenham.
Despite only having one year remaining on his current contract, Alderweireld remains content in north London and stated earlier this week that he was happy to stay at Tottenham this season.
"Yes, the release clause is running out and again anything can happen. But my focus is on Spurs and in my head I will be playing for Spurs", he told reporters when questioned on his future.
Meanwhile, Alderweireld's raised value could speed up Manchester United's pursuit of Leicester City's Harry Maguire.
Manchester United's primary target this summer is Maguire, who remains keen on a move to Old Trafford. However, Alderweireld remains a backup option should United fail to agree terms with Leicester.
The threat of a £15m increase in the valuation of Alderweireld could force United's executive vice-chairman Ed Woodward to act swiftly in wrapping up the deal for Maguire, enabling him to turn his attentions towards Tottenham's centre back before Friday should the Maguire transfer fall through.
Woodward will want to learn from the mistakes of last summer's transfer window when United failed to sign a centre back, which led to the side conceding 54 goals in the Premier League and missing out on Champions League football for the upcoming campaign.