The Mirror reckon that Barca are keen on the Belgian because of injuries to Samuel Umtiti and Thomas Vermaelen, and also due to the fact that Ajax have ruled out selling Matthijs de Ligt in January.
Alderweireld has managed to force his way back into the Tottenham team this season, but he has said recently he’s not thinking about signing a new deal at the club.
His current deal expires in 2019. Spurs do have the option to extend it by 12 months, but if they do they will trigger a a £25m release clause which can be activated in the last two weeks of the 2019 summer transfer window.
Spurs could decide to cash in before then if they receive a good offer, although selling in January may leave them short of centre-back options for the rest of the season.
At the moment Barcelona have only Gerard Pique and Clement Lenglet as their fit centre-backs. Vermaelen has been ruled out for six weeks, while it’s unclear when Umtiti will be fit to return.