De Gea finds himself in the spotlight after making a hesitant start to life as Edwin van der Sar's replacement. The £17.8 million goalkeeper was at fault for Edin Dzeko's goal in the Community Shield clash with Manchester City at Wembley, and then he allowed Shane Long's soft shot to squirm past him during the Premier League win at West Brom.
Fortunately for the Spaniard, United have got him out of trouble on both occasions, but on Monday De Gea must play a competitive match in front of his home fans for the first time.
Spurs are yet to play a Premier League match after their opener against Everton was called off, but they played some exceptional football in the midweek 5-0 drubbing of Hearts. Assou-Ekotto confirmed his team-mates are confident, and they will do their best to expose De Gea's fragility.
"We will try to take advantage of these problems he's had," the left-back said in the Sun. "When you come to England you have to learn quickly how we play here.
"It is never easy in the first six months."
Monday's game also sees the home debut of Ashley Young, whose shot let to United's own-goal winner against West Brom, but Assou-Ekotto is not overly impressed with the winger. The Cameroonian wants Spurs to go out and play the match just like a normal game.
"We used to play against [Young] when he was at Aston Villa and we did okay against him then," Assou-Ekotto said. "So it will be the same against Manchester United - he's not better just because he has changed clubs.
"Young and Nani are both good players, but they are still only human. I really don't care who I play against from Manchester United."