The Blues are one of several sides interested in the Wales star.
Nir Bitton's future at Celtic is currently uncertain, following the appointment of Brendan Rodgers.
Mark Warburton has brought eight new faces to Ibrox already this summer.
Tottenham need to add defensive cover and free agent Martin Caceres would be a quality option for minimal cost.
The 27-year-old has been linked with a switch away from Celtic
Rafa Benitez is open to selling the Frenchman, as well as Emmanuel Riviere and Yoan Gouffran.
The Wolves boss has cast doubt over the prospect of further signings in the near future.
Tottenham are reportedly in the race to sign Koln left back Jonas Hector.
Stuart Armstrong has been at Celtic for 18 months now.
The youngster has been at Euro 2016 with Switzerland.