The midfield pair are carrying ailments and will be checked closer to Sunday’s kick-off.
The White Hart Lane outfit are hoping to extend their unbeaten run with victory over the Magpies at White Hart Lane, with the North London club having ambitions of finishing in the top four this season.
Mauricio Pochettino’s men have looked impressive this term, with a competitive and competent midfield one of the standout features of their play.
Dier has been an unsung hero after moving into an anchor role, with the former defender winning his first England cap recently.
However, the former Sporting Lisbon man was taken off during Spurs’ 4-1 win over Monaco on Thursday night and as such faces a race against time to be fit to face Newcastle.
London 24 state that Dier was taken off as a precaution and as such will be assessed closer to the game.
Dembele has been rejuvenated this term under Pochettino, with the Belgian showing skill and falir for the White Hart Lane side.
However, the Belgian has been unwell with a stomach bug of late, which could force him to sit out the visit of Steve McClaren’s men.
With Ryan Mason also unavailable through injury, Pochettino will hope that at least one of Dier and Dembele is able to take the pitch against the Tyneside outfit.