UEFA Champions League 2021-22 Round of 16 Live Updates: The UCL draw takes place at UEFA headquarters in Nyon, on Monday 13 December.
No side can face another team from the same national association. Clubs cannot face opponents they met during the group stage, either.
The so-called away goals rule has been removed, so ties level after 180 minutes will go to extra time irrespective of the number of goals each team has scored at home and away. If the teams still cannot be separated after the additional 30 minutes, the tie goes to a penalty shoot-out.