Real Madrid are reportedly considering a move to re-sign Sergio Reguilon following his excellent opening to life at Tottenham Hotspur. 

Jose Mourinho resolved his left-back problem in the 2020 summer window by bringing Reguilon to north London.

The marauding full-back has made a stark impression during the early phase of his Spurs career, particularly impressing on the overlap with his pinpoint crossing ability.

The 24-year-old has racked up five assists already this term, but there is an ominous caveat to his positive form. 

Indeed, a buy-back clause was inserted into the agreement that saw Reguilon leave Real Madrid for Spurs last summer, and now Spanish media outlet Sport are reporting that Los Blancos are assessing whether to trigger that clause. 

The report claims that Ferland Mendy is struggling to convince in the left-back berth and Real Madrid may well reverse their decision on Reguilon in light of that. 

As part of the agreement signed in 2020, a fee of €45m (£40m) would force Spurs to accept an offer from Madrid and leave the 24-year-old with a decision to make over his future. 

GIVEMESPORT's Jack Saville says...

Daniel Levy may have negotiated an attractive deal for Spurs in the summer by signing Reguilon for a fee that could rise to £32m, but his shrewd approach may yet come back to bite him.

Given the extortionate prices clubs pay for full-backs in the modern era, it's fair to assume the insertion of a buy-back clause helped Levy to bring the Spaniard's price down to a modest level.

However, that short-term gain could leave Spurs back at square one in the left-back department if Real Madrid do indeed decide to trigger the reported clause. 

While there is no suggestion in the report that the Spanish giants will make a move before the January deadline, the fact they're already having second thoughts about the sale of the 5-cap international doesn't bode well. 

It's the type of news that will come as a concern to Mourinho who, having effectively exiled Danny Rose from his first-team squad, will have just one senior left-back option, namely Ben Davies, to call upon in the event that the seven-time Champions League winners re-sign Reguilon.

Reguilon's buy-back clause leaves Spurs in a genuine catch-22 situation.