In the closing stages of the fixture at White Hart Lane, Alli was harshly cautioned after a seemingly innocuous collision with an opponent, but the referee deemed it worthy of a booking.
Spurs progressed through to the last 16 of the competition with a 3-0 victory, but the 19-year-old will miss the first leg of the next tie as a result of the offence.
Alli said: "It was disappointing because obviously you want to play as much as you can but the great thing about the team this season is that we have great depth.
"It was the referee's decision to give the yellow card and I have just got to move on and get ready for when I am back."
The England international has come in for criticism of late after becoming involved in a couple of heated moments with the opposition, most notably against the Serie A outfit last Thursday when he appeared to kick out at Nenad Tomovic.
Alli was fortunate to avoid being sent off on that occasion, but he found that luck was against him in North London and he will now have to take a watching brief when his teammates next take to the pitch in Europe.
The draw for the next round of the competition will take place on Friday lunchtime.