Spurs are pushing to sign a centre-back before the transfer window slams shut next week and Inter’s Milan Skriniar is a key target.
However, the north London club have been forced to consider alternatives after struggling to strike a deal with the Italians for the Slovakian.
Chelsea central defender Rudiger, who has also attracted interest from French champions Paris Saint-Germain, has emerged as an option for Jose Mourinho’s side.
The Stamford Bridge outfit are also aware of Tottenham’s interest in their 27-year-old centre-half.
However, it remains to be seen if Chelsea will be willing to let Rudiger move across the English capital and join their rivals should Spurs make a formal offer.
The Blues could also ideally want the former Roma man to sign a contract extension before sanctioning a loan move, with only two years left on his current deal.
Tottenham are still working on a deal to sign Skriniar from Inter, but with the clubs still apart in their valuation of the player and time running out, could turn to other options, with Rudiger one of them.