The Belgium forward moved to the Black Cats on a season-long loan from Manchester United in the summer transfer window as Januzaj looked to secure regular first-team football after seeing his Red Devils career stall in recent seasons.
Januzaj has been reunited with his former United manager David Moyes and the 20-year-old has already scored his first goal for Sunderland in a victory over Shrewsbury Town in the League Cup last month.
Dembele has played alongside Januzaj during Belgium duty and has no doubts surrounding the winger’s raw talents ahead of Sunderland’s visit to north London in the Premier League’s late kick-off.
“I haven’t had any conversations with them but I know they are very good players,” Dembele told Tottenham’s website.
“Adnan can make the difference, Jason is a very good defender as well – they are young men but of course we want to win all our games and we have to win it this weekend.
“It was a disappointing night for us against Monaco. Everything was set up to be right and to win the game, but I think mentally we are strong enough to win this game on Sunday, to not feel pressure and just do our job. We have to win it and we have full confidence for that.”
Tottenham are unbeaten in the Premier League so far this season after collecting eight points from a possible 12 in their opening four games.
Dembele was powerless to prevent Spurs from suffering a 2-1 loss to AS Monaco in their Champions League group-stage opener in mid-week.
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